Naantali are some important points of interest in the city, such as the Moomin World theme park on the island of Kailo. Naantali Spa Hotel, the largest spa in the Nordic countries, and the Naantali’s medieval convent stone church. The city's popularity as a tourist venue is highlighted by the fact that the official summer residence of the President of Finland, the Kultaranta estate, is located on Luonnonmaa. The archipelago sea boat traffic is handled by S/S Ukkopekka. Old steamship cruise Naantali-Turku-Naantali. Naantali hosts an international music festival every June, and the traditional Sleepyhead Day carnival in July. In addition to
Finnish name share the same surname. All persons have the right to change their surname once without any specific reason. A surname that is un-Finnish, contrary to the usages of the Swedish or Finnish languages, or in use by any person resident in Finland cannot be accepted as the new name, unless valid family reasons or religious or national customs give a reason for waiving this requirement. However, persons may change their surname to any surname that has ever been used by their ancestors, if they can prove such claim. Surnames behave like regular words when forming grammatical cases. Thus, for example,