Around 19km before you reach Blönduós, a quick 6km detour along Rte 721 leads you to a precious stone church, Þingeyrar, sitting quietly and photogenically on Hóp lagoon. The current structure was erected in the 1860s, but 800 years earlier the site hosted a district þing (assembly) and a Benedictine monastery. There's a small museum here too.
