This curious object is a sundial. The upper "knob" on both faces is for 22 December to 22nd June, the lower for the 22nd June to the 22nd December. If you zoom in, you can see curved lines and a pinprick of light on the bronze plate. The dot is on the line for 9.30am, which is when I took the photo.

Pentax K-3iii, SMC Pentax-DA* 50-135mm f/2.8 lens.