Arruan Haundi [en: "Great Arruan", the root of the word goes back to Iron / Blacksmiths] is an old 16th century farmhouse. It has a coat of arms in the main facade and was back then owned by a baron. For over 400 years the inhabitants have been working with humility and knowledge of preserving the values ​​of our culture and the respect for the environment.

The Lastur valley is located in a karst area forming a natural corridor the mountains of Izarraitz and Arno at the end. In addition to some hiking trails, countless caves and sinkholes invite you to discover the landscape. In the neighboring village of Zestoa on can find the cave Ekain, an important testimony of past cultures, the original rock paintings inside the original cave are available for visitors in form of a replica.

The Lastur valley is part of a geopark on the Basque coast between Mutriku and Zumaia. The main park along the rocky cliff can be visited by boat or by walking on a part of the northern Way of St. James. The spectacular cliffs are made up of rock layers that depict the history of Earth's evolution over Milllions of years like pages in a book. Geologists from all over the world ​​have already visited the so-called Flysch [originally a word from Switzerland - "flow"] to study these rock formations.