Three-sided obelisk in Riegrovy sady, sandstone obelisk in Vinohrady, Prague, Czech Republic

The Three-sided obelisk in Riegrovy sady is a slender, tapering sandstone obelisk with a triangular base, carved by an unknown author using the cutting method. It stands on a cuboid plinth bearing reliefs of a bird family, the allied coats of arms of the Canal family. It occupies the northeastern part of the park in Vinohrady, Prague 2.

The obelisk was erected in 1810 by Count Josef Emanuel Canal of Malabaila (1745–1826) in memory of his wife Brigitta Taafe Canalová, daughter of Rudolf Chotek, who died that year. It stood in the Kanálka garden, the grounds that later became Riegrovy sady. The sandstone monument is the work of an unknown sculptor, cut rather than modelled.

The obelisk stands in Riegrovy sady, laid out on the grounds of the former garden Kanálka of Count Josef Emanuel Canal z Malabaily. Its base carries reliefs of a bird family, the allied coats of arms of the families. The name Ptačí obelisk, bird obelisk, comes from these reliefs.

The monument is located along the park's main paths and can be easily found by following directions from the lookout tower area toward the open green spaces. You can visit and view the sculpture freely at any time as it stands in an accessible part of the park.

The obelisk's base is carved with reliefs of a bird family — the heraldic alliance symbols of the Canal and Taafe families. The slender three-sided shaft, cut rather than built up, is the work of an unknown sculptor.