It should be known to fans of the "Game of Thrones", as the location of the Dragonstone castle.
To get to the island, you must first come to the tourist center with a restaurant, souvenirs and a large parking lot. Then we go down the equipped path and visit viewpoints along the way.
View of the neighboring island of Akatxa Irla where live only birds and hares.
At the bottom there is a toilet and drinking water, but it is better to take a bottle with you, just in case. It can be really hot here in the summer.
After going down, there is still a rise to the chapel. In general, the place is beautiful and very popular. We visited in the fall and at sunset, so there were not so many people.
We spent the night nearby at the Apartamentos Turísticos Rurales Ureta (booking.com). This is a convenient place to visit Gaztelugatxe. Although you can come on a day trip from Bilbao.
Getting there: parking N 43 26.451 W 2 47.044. From Bilbao (Plaza Moyua Square), take the A3518 bus (map) to the San Pelaio bus stop in Bakio. Buses run frequently. From there 2.2 km on foot along the sea to the parking lot Gaztelugatxe. The elevation is 160 meters, therefore, you can save energy and take a taxi. You can also try to change onto the A3524 bus to Bermeo (map), it goes to the Gaztelugatxe parking lot (Gaztelu Begi stop).