Resident Evil 4, Castle

Leon and Ada find the Elegant Chessboard in different rooms in the Salazar Castle.

Resident Evil 4, Castle and Island

There are target practice games in the Salazar castle and the Island. Beating them successfully rewards you with bonus money for use in-game and if you beat them all, you get some extras as well.

Resident Evil 4, Castle dungeons

While playing as Ashley, you have to solve a sliding puzzle in order to proceed.