Preah Suramarit National Theatre, Phnom Penh, inaugurated November 12, 1968. Architect: Vann Molyvann. The theatre burnt in 1994 and was demolished in 2008. The photo is from 2007.
For a history of the architecture and architects of the time, see: "Building Cambodia: New Khmer Architecture 1953-1970" by Helen Grant Ross and Darryl Leon Collins, with preface by HM King Sihamoni. The Key Publisher, Bangkok 2006. ISBN 974-93412-1-X
The projection used for the exhibition image (0.75 x 1.5 m) is a transversal equirectangular projection. Info: http://en.wikipedia.org/wiki/Map_projection. It shows the floor and ceiling in an interesting way. My normal image format for spherical panoramas is equirectangular, 360 degrees wide, 180 degrees high, see below:
For an interactive panorama in a "normal" projection.
See also a full series of panoramas of the theatre