Test scenes of spica can be downloaded from following links. Also, these files can be downloaded with scenes/download.py.
Bidirectional path tracing (256 spp) - Download
This is a scene for Ray tracing camp, which is a Japanese domestic event for ray tracing fans.
Stochastic progressive photon mapping (1000 spp) - Download
Gradient-domain path tracing (256 spp) - Download