Temple Hill is steep (with artificially created steepness) and about 30 m high, and it is opposite Marijas Island. It is an ancient Lettigalian castle hill, 80 m long and 40 m wide, with several artificial ramparts. One of the oldest objects found in the region is an axe from the 2nd to 3rd millennium BC. Archaeologists believe that the island was populated at that time. There was a Lettigalian castle on the hill during the 10th and 11th century, but it was sacked by the Holy Crusade. The surface of the castle hill was transformed comparatively recently in 1807, when a granite rotunda was built there in honour of Russian Field Marshall Sheremetev and Swedish captain Wulff. The view of Lake Alūksne and the town is one of the most beautiful ones in all Vidzeme. The Sun Bridge (1937) is also worth a look. A wooden viewing platform is nearby.