The historic centre of Constance is one of the best-preserved medieval old towns on Lake Constance, with cobbled lanes, painted facades, and quiet inner courtyards arranged around the cathedral and the harbour. The town survived the Second World War undamaged thanks to its unusual position on the Swiss border, and many of the buildings standing today were already trading houses, inns, and guildhouses during the late Middle Ages. Wine taverns, artisan workshops, fashion boutiques, and small cafés have taken over many of the slightly leaning old buildings, and the network of small squares and alleys rewards an unhurried half-day on foot. The town has been a university city since 1966, which gives the historic streets a lived-in, year-round energy quite different from the more strictly seasonal feel of the smaller lakeside towns nearby.

At the centre of the old town rises the Cathedral of Our Lady (Münster Unserer Lieben Frau), a Romanesque and late-Gothic building whose origins reach back to the early Middle Ages. The cathedral served as the seat of the Bishop of Constance for over a thousand years and stood at the heart of the great Council of Constance held here between 1414 and 1418, the largest religious gathering of the medieval world. The interior preserves a remarkable cycle of decoration from many centuries, including a striking spiral staircase, a Romanesque crypt, and intricate Gothic vaulting. A short walk away, the medieval Church of St Stephen and the elegant Lutheran Church of St Augustine add further architectural layers, while the surrounding lanes are dotted with smaller chapels and monastic buildings that recall the city’s long ecclesiastical past.

Down by the harbour stands the Konzilgebäude, the Council Building, a long stone warehouse from 1388 that gave the Council of Constance its meeting space for the conclave that elected Pope Martin V in 1417. The building still anchors the lakeside skyline and now serves as a cultural venue, while the surrounding Seepromenade stretches in both directions along the water. The promenade is lined with public gardens, lakeside benches, sculpted hedges, and small piers where ferries arrive and depart for towns across Germany, Switzerland, and Austria. A short walk further along the lakefront, the Sea Life Constance aquarium offers a more compact lake-themed family attraction, with displays focused on the freshwater ecosystems of Lake Constance and the Rhine alongside tropical marine tanks.

At the very entrance to the harbour, on a small stone pedestal that rotates slowly through a full circle every four minutes, stands one of the most unusual public sculptures in Germany. Imperia, designed by the Bodensee sculptor Peter Lenk and installed in 1993, is a nine-metre concrete figure of a richly dressed courtesan holding two tiny naked men in the palms of her outstretched hands: one wearing a papal tiara, the other an imperial crown. The work is a satirical commentary on the morals of the Council of Constance, when Europe’s most powerful clerics and rulers gathered here for four years to end a schism in the church. The statue was controversial when it appeared and was put up without official approval, but it has since become the most photographed landmark in the city and a symbol of the lakeside character of Constance itself, where history is taken seriously but never reverently.

At the heart of Mainau Island stands a graceful Baroque palace built in the eighteenth century for the Teutonic Order of Knights, who held the island as a regional commandery for more than five hundred years. The palace rises above the treetops on the highest part of the island and is visible from far across the lake, its pale facade and elegant gables echoed in the smaller Palace Church of Saint Mary beside it. The church is one of the finest examples of southern German Baroque ecclesiastical architecture, with painted ceilings, stucco work, and an unusual harmony of scale that suits its garden setting. The island has been in the hands of the Bernadotte family, descended from the Swedish royal house, since the late nineteenth century, when Grand Duke Frederick I of Baden married into the family and began the long process of transforming the estate into a public botanical garden.

Below the palace terrace, on a gentle southern slope facing the lake, the Italian Rose Garden opens out as one of the most photographed corners of Mainau. The garden was laid out in 1871 under Grand Duke Frederick I, with geometrical parterres, fountains, and pergolas arranged around a central axis in the Italian Renaissance style. Roughly nine thousand rose plants flower across the island between June and August, in colours that range from deep crimson and apricot to soft pinks and pure whites. Old climbing varieties, modern English roses, and rare historical cultivars are grown side by side, with information panels explaining each one for visitors with a serious interest in the subject.

On the southern edge of the island stands the largest butterfly house in Germany, a tropical greenhouse home to over a thousand free-flying butterflies of around eighty different species. Visitors walk along a winding path through a recreated tropical landscape of ferns, orchids, and small streams, with butterflies emerging from cocoons in a glass display case and feeding on slices of fruit set out along the route. A short walk away, the Palm House holds a collection of around 1,200 orchids alongside palms and exotic plants, and during the cooler months the same building hosts seasonal exhibitions of citrus trees, lilies, and other rotating thematic displays.

A short walk from the rose garden, the Italian Water Cascade descends in a long stepped flow of water from the upper terraces of the gardens toward the lake. The cascade is framed by Mediterranean planting, including palm trees, olive trees, lemon and orange trees, and giant sequoias, all of which thrive in the unusually mild lakeside climate. The composition draws on the great Italian Renaissance garden tradition of Tivoli and the Villa d’Este, scaled down for the island and adapted to the cooler northern light. In summer the surrounding terraces are filled with thousands of seasonal flowering plants, and in autumn the same beds are replanted with the famous Mainau dahlia displays, which have become a destination in their own right.

Bicycles are not permitted on Mainau Island itself, which is reserved entirely for pedestrians once visitors cross the bridge or arrive by boat. Secure bike parking and lockers are available at the entrance to the island, on the mainland side of the connecting footbridge, where bikes can be left for the duration of the visit. The island is small enough to be explored entirely on foot, with most of the main attractions reachable within a thirty-minute walk of each other along marked paths. Comfortable walking shoes are recommended, particularly for visitors planning to combine the gardens, the palace, the butterfly house, and the lakeside terraces in a single half-day or full-day visit.

Constance’s main railway station sits directly beside the harbour at the edge of the old town, with the cathedral, the Council Building, the lakeside promenade, and the Imperia statue all reachable on foot or by bike in under ten minutes. Cycling infrastructure in and around the city is excellent, and the lakeside promenade itself doubles as a long, flat cycle route that connects easily with the wider Lake Constance Cycle Path (Bodensee-Radweg). Bike racks and bike parking are available at the station for shorter or longer stops.

For Mainau Island, the most pleasant way to continue from Constance is by bike, with a flat ride of around twenty minutes along the lakeshore that follows signposted cycle paths through the suburbs of Staad and on toward the island bridge. The same route can also be covered by local bus or by boat from the harbour, with regular sailings during the main season. As bicycles are not permitted on Mainau itself, visitors arriving by bike leave their machines at the secure parking area on the mainland side of the bridge before crossing on foot. For onward travel, the same rail and boat connections link Constance back toward Radolfzell, Tuttlingen, Überlingen, Friedrichshafen, and the wider Danube and Lake Constance corridors, so the city and the island together work equally well as a one-day excursion or as a longer two-night base.