The main day trip is to the Wadden Islands of Vlieland and Terschelling — both reachable from Harlingen by the morning ferry, both worth a full day. Inland, Franeker is twenty minutes by train, with the famous Eise Eisinga Planetarium (the oldest working planetarium in the world). Bolsward, a similar distance south, is a small Hanseatic town with one of the finest late-Gothic town halls in the Netherlands.