Belur is usually visited as part of a Hassan district circuit. Sravanabelagola, with its great monolithic Jain statue, is the strongest linked stop and can be combined with Belur in a long day from Bangalore or Hassan.
Halebidu is only about 16 km from Belur and is essential if you care about Hoysala art. It does not yet have a separate World66 location page, but the Hoysaleswara temple and Jain basadis are covered here as Belur-area sights.