Sandbox
Sandbox is a Polygon LAND Purchase, Wallet Confirmation and Resale Workflow
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Sandbox is the practical purchase path for selecting a LAND parcel on Polygon, paying with SAND, confirming the ERC-721 token in the signing wallet and preparing it for resale. Begin on The Sandbox Map, compare the parcel's coordinates and contract details, then use either an active public LAND sale or the linked OpenSea order. The wallet must be connected to Polygon PoS, hold the required Polygon SAND for an official sale and have POL available when a network fee is requested. After signing, confirm the transaction hash, token ID and owner address before treating the interface as settled. A later exit uses an OpenSea listing or an existing offer, with the same token and chain checked again.
The Sandbox Map Versus OpenSea for Parcel Selection
The Sandbox Map and OpenSea answer different questions before a buyer commits to a Polygon LAND parcel. The Map shows coordinates and neighboring estates; OpenSea shows the owner, order type and payment token. Use the Map first, then match its parcel to the marketplace item. A single 1x1 LAND has a 96x96-block base and a 128-block height. Each block represents 1 meter, while 32x32x32 voxels compose one block. Location and order terms separate parcels that share the same 96x96-block base.
Preparing Polygon, SAND and the Signing Wallet
A ready Sandbox purchase setup links one wallet to the correct account, network and token balances before selection.
Polygon PoS mainnet uses chain ID 137 and POL as its native gas token. Add the network in MetaMask or Coinbase Wallet, then connect through The Sandbox's supported flow; WalletConnect routes other compatible wallets. Polygon SAND is an ERC-20 token at contract 0xbbba073c31bf03b8acf7c28ef0738decf3695683 and uses 18 decimal places. Importing it changes the wallet display, not ownership. The Polygon LAND contract is 0x9d305a42A3975Ee4c1C57555BeD5919889DCE63F, and the wallet must transact ERC-721 items. A wallet previously linked to one Sandbox account can't be linked to a different account, so settle the address choice before funding it.
For an official public LAND sale, complete Know Your Customer verification before the sale begins; the published preparation window allows up to 48 hours for review. Hold enough Polygon SAND for the chosen Regular or Premium category, plus POL unless the interface offers a gasless or SAND-paid route. For an OpenSea order, match the chain and consideration token exactly as the wallet displays them. Ethereum SAND and Ethereum LAND occupy different chain positions even when their ticker and artwork match, so the prepared route ends on Polygon chain ID 137.
Completing One Polygon LAND Purchase
A Polygon LAND purchase completes when the buyer signs one order and the ERC-721 transfer settles to that wallet.
In a public sale, choose one of two categories: Regular or Premium. The official sale assigns a random available parcel through its published flow, and each completed purchase acquires one LAND. Repeat the process for another parcel rather than assuming a cart contains several. The Sandbox map has a fixed total of 166,464 LAND parcels. This supply is encoded independently of the temporary sale inventory. That cap doesn't describe live availability, so the actionable screen is the active sale allocation. Read the coordinate after assignment and retain the transaction hash alongside the token ID.
For a secondary purchase, OpenSea presents three actions: buy a fixed-price listing, bid in an auction or make an offer. Choose one primary action and read the wallet request before signing. A purchase request should name Polygon, the LAND contract and the expected consideration. An offer only creates an order until the owner accepts it, whereas a filled listing transfers the token during settlement. Return to the Map after completion and match the acquired coordinate to the item recorded in the wallet.
Can You Confirm LAND Ownership Before the Interface Refreshes?
Yes, Polygon LAND ownership is confirmed onchain from the transaction receipt, contract address, token ID and owner address.
Copy the transaction hash from MetaMask, Coinbase Wallet or OpenSea and inspect it in Polygonscan. A successful receipt should include an ERC-721 Transfer event for contract 0x9d305a42A3975Ee4c1C57555BeD5919889DCE63F and the selected token ID. An EVM owner address is 20 bytes, displayed as 40 hexadecimal characters after 0x. A transaction hash is 32 bytes, displayed as 64 hexadecimal characters after 0x. The ERC-721 ownerOf call should return the same wallet address that received the LAND.
Polygon PoS milestones typically give deterministic finality in 2 to 5 seconds after validators agree. A wallet or profile index can refresh later, so separate chain settlement from interface display. Check the receipt status first, then the current owner and finally the token balance. The Sandbox profile should use the identical connected address; switching accounts or networks explains many apparent mismatches. Once the contract, token ID and owner agree, the purchase position is confirmed before the thumbnail appears in The Sandbox.
Listing the ERC-721 LAND for a Clean Exit
A clean LAND resale starts by confirming ownership, choosing an OpenSea order type and signing only the intended authorization.
OpenSea supports two main sale paths for an owned LAND: create a listing or accept an existing offer. A manual listing records the payment token, amount and expiry, while an accepted offer settles against terms already signed by the bidder. Listing duration runs from a minimum of 15 minutes to a maximum of 6 months. The first listing for a collection may also request an onchain approval before the separate order signature.
Worked Example. Every changing input here is hypothetical: parcel coordinate (24, -18), token ID 412, purchase amount 1,200 SAND, resale amount 1,350 SAND, listing duration 7 days and acceptance on day 3. The buyer first signs the purchase and confirms that ownerOf(412) returns the buyer's address. That owner then creates the seven-day order for 1,350 SAND. When another wallet fills it on day 3, ownerOf(412) changes to that wallet and the seller's LAND balance moves from 1 to 0. No other parcel, balance, time or market value is implied by those invented numbers.
After signing a listing, open its order view and read four fields: chain, token ID, payment token and expiry. The LAND stays in the owner's wallet while the order is active; a listing isn't a custody transfer. If the amount or expiry is wrong, cancel or replace the order through the marketplace flow. An onchain cancellation produces its own transaction receipt, while an expired order stops meeting its signed time condition.
For an immediate exit through an offer, inspect the offered token and the seller proceeds displayed before signing. Acceptance settles the ERC-721 transfer and payment together through OpenSea's contracts. Confirm the new owner in Polygonscan, confirm the payment token in the selling wallet and check that the marketplace no longer shows an active order. The completed example ends with token ID 412 owned by the purchasing wallet. The related mechanics are detailed in Sandbox rewards.
The Onchain Ownership Trail Behind the Workflow
The LAND ownership trail joins one ERC-721 identifier, two wallet addresses and a Polygon transaction receipt. ERC-721 defines each token ID as a uint256 value, a 256-bit field whose apparent sequence carries no meaning. Its Transfer event records the sending address, receiving address and token ID; ownerOf returns the current owner. SAND follows ERC-20 accounting separately. An OpenSea order changes no LAND state until settlement, after which The Sandbox and Polygonscan read the same contract state. This closes the record on Polygon chain ID 137.
Sandbox - your questions answered
Can a Ledger hardware wallet sign a Polygon LAND purchase?
Yes, a Ledger device can sign a Polygon LAND purchase when it is connected through a compatible interface such as MetaMask. The address shown on the hardware screen must match the wallet linked to The Sandbox account. Select Polygon chain ID 137, review the LAND contract and token action on the signing screen and confirm the resulting transaction through that same address.
Does a LAND resale automatically include its published Experience?
No, transferring the LAND token doesn't automatically transfer a separately managed Experience or its associated assets. LAND supplies the location used for publication, while an Experience has its own ownership and deployment controls. A resale that includes additional content needs those items identified and transferred separately. Confirm the ERC-721 LAND ownership change first, then review each accompanying asset under its own token ID.
When should SAND be bridged before a public LAND sale?
Bridge SAND before the sale window if the balance currently sits on Ethereum and the official purchase requires Polygon SAND. The transfer includes source-chain and destination-chain processing, so its completion time isn't the moment to discover a network mismatch. Finish the bridge, confirm the Polygon token balance under the SAND contract and retain enough POL if the purchase screen requests native gas.
Does transferring LAND to another wallet remove an OpenSea listing?
Transferring LAND away makes an active OpenSea listing inactive because the listing wallet no longer owns the token. The signed order can matter again if the same LAND returns to that wallet and its original conditions still hold. Review inactive orders after any transfer and cancel an order that should no longer be fillable before reauthorizing the collection for another sale.
Are adjacent LAND parcels resold together as an Estate?
Adjacent LAND parcels can be resold as one Estate only after they have been assembled into an Estate token through The Sandbox process. The defined Estate sizes are 3x3, 6x6, 12x12 and 24x24 LANDs, representing 9, 36, 144 and 576 parcels. Until assembly is complete, each 1x1 LAND remains a separate ERC-721 item with its own token ID and order.
Will OpenSea accept funds from another chain for a Polygon LAND purchase?
OpenSea supports cross-chain checkout for eligible NFT purchases when its interface presents a valid source token and route. The payment starts from the selected balance, while the acquired LAND still settles on Polygon under its ERC-721 contract. Read the wallet sequence carefully because a routed checkout can require more than one signature or transaction before the Polygon owner address changes.