Here's Bowser's Castle from Super Mario All-Stars versions of Super Mario Bros. 1 and Super Mario Bros. 2: The Lost Levels.
Comes with 3 different .def files:
SMB1_Castle: Normal Floor, with Goombas
SMB1_CastleNoGoombas: Same as above, but without Goombas
SMB1_CastleBridge: Bridge where you fight against Bowser
(Note: Shadow.exe and Rouge.exe on screenshots are not mine, they are made by Pizzasause. Tails.exe and Cream.exe (also on screenshots) are currently my projects that I'm working on)
Link: https://www.dropbox.com/s/vmon4xw12sb2er3/SMB1_SMAS_Castle.rar?dl=0