The Martenahuis is a late-medieval town palace in the centre of Franeker, built in the 1490s for the local Marten family — a small, brick-fronted complex with a stair tower, mullioned windows, and a small inner garden. From 1819 to 1843 it housed the so-called Athenaeum, the truncated successor to Franeker's university, after Napoleon abolished the original.
It is now a museum of Franeker's history, with rooms dedicated to the university and to the town's golden-age scholars. Combined with the Eisinga Planetarium and the City Hall, the Martenahuis makes a satisfying short circuit of the historic centre.