Sandcastle

The Sandcastle is located in Treasure Trove Cove. It is where all the Cheat Codes in Banjo-Kazooie are entered.

One of the codes for the sandcastle is used to unlock Treasure Trove Cove. But that doesn't make sense because the sandcastle is located within Treasure Trove Cove. So one might say that the Sandcastle was to be originally located in Mumbo's Mountain. Much like how the Code Room for Banjo-Tooie was located in the first world, Mayhem Temple.