According to forum posts, San Sebastian - Donostia is well-served by various bus companies including ALSA, PESA, and Euskotren, offering frequent services. For instance, there’s a direct bus from Bilbao Airport to Donostia-San Sebastian running hourly from early morning until late at night.

Travelers have noted that the buses are modern and equipped with amenities such as toilets and often make stops for food and restroom breaks on longer journeys. The buses are generally comfortable and suitable for carrying luggage, making them a convenient option for travelers moving between cities or exploring the region.

Some travelers have mentioned the ease of booking tickets online in advance, which is recommended to ensure availability, especially during peak travel times. This can be done through the official websites of the bus services like ALSA and PESA, enhancing travel planning for visitors.

According to forum posts, for those interested in history and culture, the San Telmo Museum, housed in a 16th-century convent, is recommended. It features murals by José María Sert and hosts both permanent and temporary exhibitions. The Gothic Church of San Vicente and the Baroque-style Santa María del Coro are also notable historical sites.

Some travelers suggested visiting the Tabakalera cultural center for various exhibitions. The Chillida Leku museum is noted for its modern art collections, though much of it is outdoors. The Aquarium, which includes a maritime museum, and the nearby sea museum (Euskal Itxas) are also recommended, especially during inclement weather.

For families, forum users recommend the beaches such as Playa de la Concha, which is safe for swimming and has facilities like free showers and lockers. Zurriola beach is popular for surfing but noted for its stronger currents. Day trips to nearby towns and cities like Hondarribia, Bilbao, and Pamplona are suggested for more exploration.