Day trips: Schwetzingen, Speyer, Neckarsteinach
Three day trips are worth it, all by S-Bahn. Schwetzingen is 15 minutes away: the Electors' palace garden (CHF 8 in summer, CHF 5 in winter, about EUR 9 and EUR 5) is one of the great baroque gardens of Europe, with a mosque, a temple of Apollo and a rococo theatre, 72 hectares, so allow two to three hours. From April to June it is asparagus season, Schwetzingen asparagus is a household name in Germany, the stalls stand on the Schlossplatz, and a plate of asparagus with ham costs CHF 20 to 26. Speyer is 45 minutes away: the Imperial Cathedral of 1061 is the largest surviving Romanesque church in the world and a UNESCO World Heritage Site, admission free, imperial crypt and tower CHF 8. The medieval Jewish courtyard with its mikveh has also been World Heritage since 2021 (CHF 4). The Technik Museum Speyer with a Boeing 747 on stilts and a Russian space shuttle costs CHF 22, children love it, allow half a day. Neckarsteinach, 15 minutes upstream, has four castles on one ridge and a two-hour circular walk; the return trip on a boat of the Weisse Flotte (CHF 12) is the most beautiful way to arrive in Heidelberg. Mannheim, 15 minutes away, is not pretty, but it has the best art gallery in the region (CHF 11) and Turkish food in the Jungbusch quarter that is worth the trip.