In 3 hours, you can do a nice route combining the Old Town and the Modern Area. For example: starting in the Old Town, strolling through its narrow streets, passing the Arriaga Theatre (outside), Santiago Cathedral, and Plaza Nueva. Then, walk along the entire estuary, enjoying the surroundings with modern buildings and bridges like the Zubi Zuri Bridge and the Isozaki Towers, until you reach the Guggenheim Museum area. Here you'll find many outdoor sculptures. From there, following the estuary, you can reach the Euskalduna Palace and further on, the Maritime Museum (outdoor section). The museum also has accessible exhibitions with information in English. You can finish with some pintxos on the terrace of the Maritime Museum bar. All of this is within walking distance. Furthermore, since it's a flat area, it's suitable for wheelchair users.

Second option: History and Sports, especially for football fans. Starting in the Old Town, along the Paseo del Arenal, passing through Plaza Nueva (a pintxo bar), Santiago Cathedral, and the Bar de la Peña del Fútbol (a bar with photos and trophies of the players), continue along the estuary past the City Hall, the Guggenheim Museum, or along the Gran Vía de Diego López de Haro, the founder of the town. From there, you'll reach the modern area and the football stadium. Here you have the option of visiting the museum on your own or simply having a drink in the café overlooking the stadium.

The main attractions in Bilbao are: the Old Town, the Guggenheim Museum Bilbao, the Museum of Fine Arts, the Azkuna Centre, the Cathedral of Santiago (in the Old Town), and the Basilica of Our Lady of Begoña, patron saint of Bizkaia. Other areas not far from Bilbao but of great interest include the Vizcaya Bridge (a World Heritage Site and the world's first transporter bridge), the coastal towns of Bermeo, Bakio, and Mundaka (towns steeped in history, about an hour from Bilbao, but well worth a visit), and San Juan de Gaztelugatxe, the second most visited place after the Guggenheim Museum. The series Game of Thrones (Dragonstone) was filmed at San Juan de Gaztelugatxe.

Gastronomy and history. This would be a pintxo route, starting in Plaza Circular and heading towards the Old Town, visiting the small, traditional bars. Alternatively, you could go from the same plaza to the modern part of the city, where office workers gather during their breaks for pintxos. You could finish by taking the funicular up Mount Artxanda and enjoying the panoramic views of the city. Or you could visit the Alhóndiga Cultural Center, which also has pintxo bars and restaurants.

Bilbao is a small city and easy to explore on foot. It's also very accessible for seniors, people using walking sticks, or wheelchairs. Distances aren't long, but if you need public transport, the best option is the tram, as it offers views of some of the city's modern monuments. The tram system is also very efficient and inexpensive compared to other European cities.

Yes, from Bilbao you can take the metro towards Plentzia to reach the beach in less than 30 minutes. The beach is a 10-minute walk from the metro station.

In Bilbao, the most popular fish is cod, so almost every restaurant offers it prepared in two different ways: cod pil-pil style or cod Bizkaia style. Near Plaza Nueva, or even right in the square, you'll find restaurants serving cod pintxos, or simply cod as I mentioned earlier. The Basque Country is rich in seafood and produce, which is why its food, especially its pintxos, is such an integral part of the culture. There are 34 Michelin-starred restaurants in the Basque Country alone, and five of them are located in the city center of Bilbao.

To get to the oldest transporter bridge in the world, you have three options. 1) Take the metro. It only takes 25 minutes, depending on your starting point, but always head towards Plentzia. Get off at the Areeta station and from there it's a 5-minute walk to the transporter bridge. 2) Take the bus. The Bizkaibus line departs from Abando Station, although it's not the most recommended option due to traffic. (40 minutes, depending on the time of day due to traffic). 3) Take the train from Abando Station. (This takes about 15 minutes and is a pleasant journey through the towns in the area. Get off at Portugalete Station, and you'll immediately have views of the estuary and the Bizkaia Bridge.)

The coastal towns, such as Bakio, Bermeo, and Mundaka, are steeped in history and culture, and offer excellent cuisine. (For a 100% Basque translation, see below.) The Urdaibai area, the entire region, and the Txorierri area near the airport are ideal for walks along the beach or through nature. Part of the Camino de Santiago coastal route passes through some of these towns.