The town twinning has its origins in a vacation trip by Armin Klein, a volunteer city councillor in Wiesbaden at the time. In the two years that followed, numerous contacts were established between the two cities on his initiative. At the suggestion of the Committee of Elders, the contacts deepened and finally led to the signing of a partnership agreement on June 15, 1981.

The city of San Sebastian, which has a population of around 187,000, is considered the tourist capital of the Basque Country and is also famous for its excellent Basque cuisine.

One of the most beautiful bays in Spain, three urban beaches and a charming old town are some of the popular tourist attractions, which also include the port of the Basque city. San Sebastian is considered by many to be the tourist capital of the Basque Country. The city has one of the world's most beautiful bays, La Concha, as well as three urban beaches (La Concha, Zurriola and Ondarreta). Zurriola beach in particular attracts many surfers from home and abroad.

San Sebastian is surrounded by mountains and viewpoints (Igeldo, Urgull, Ulia and Santa Clara Island), while the River Urumea gives the city structure.

Sights include the old town with its numerous pintxo bars, the town hall and the old casino as well as the Buen Pastos Cathedral, the Palace of Miramar, the Victoria Eugenia Theatre, the Kursaal (event center) and the Peine del Viento (wind comb) by the artist Chillida. Alongside Wiesbaden's twin city of Wroclaw, San Sebastian was also voted European Capital of Culture in 2016.

The partnership between the cities of Wiesbaden and San Sebastian is very lively. This is reflected in numerous different activities. These include cultural encounters, school exchanges and sporting competitions. The town twinning is also maintained on the Wiesbaden side by the twinning association "San Sebastian e.V.", which was founded in 1983. (opens in a new tab)