A modular play structure for animals has base and platform pieces with connector mechanisms, such countersunk bores, spaced apart by a standard distance. Thus platforms and bases can be oriented in multiple directions and are interchangeable. Columns space the bases and platforms vertically. Columns may be of varying height, preferably with different heights described by a common factor. Stacked columns are connected end-to-end with a spacer of the same thickness as a platform interposed therebetween. Columns are oriented in the same direction with female and male ends connecting with platform, base, and adjacent columns.
