The Takeda Clan Residence, also known as Tsutsujigasaki Mansion Ruins, was the fortified home of the last three generations of the Takeda clan in Kofu, Yamanashi Prefecture, Japan. Built in 1519 by Takeda Nobutora, it was unique among Japanese castles for being located on flat land rather than a mountain, emphasizing its role as an administrative center rather than a pure military fortress.

The complex had two main enclosures surrounded by moats, with the ruler's private residence in the central courtyard and administrative buildings in the west.

After Takeda Shingen's death in 1582 and his clan's downfall, the stronghold was abandoned. Today, the site is protected as a National Historic Site and contains the Takeda Shrine and a museum dedicated to the clan's history, with some original moats and stonework still visible.