Santoña Marshes and Collado de Asón Loop

This route is classified as a 'Hard road ride' and demands very good fitness from cyclists. It features a significant elevation gain of over 1,900 meters across approximately 102 kilometers.

On average, this route takes around 5 hours and 34 minutes to complete, though this can vary based on your fitness level and stops along the way.

The route offers varied terrain. While much of it is asphalted, be aware that some segments, particularly on climbs like Collado Espina within the Collados de Asón Natural Park, can have mixed road conditions. You might encounter rough, bumpy sections, and short concrete stretches designed to aid grip on steep parts. There are also mentions of unpaved segments that may be difficult to navigate on a standard road bike, so be prepared for varied surfaces.

The route is celebrated for its diverse and picturesque scenery. Key highlights include the stunning views of the Santoña Marshes, which are ideal for bird watching. As you head inland, you'll experience the challenging ascent to Collado de Asón, offering rugged mountain views. Other notable spots include the Weir and slide at Coterillo on the Asón River and the Ampuero Climb.

As this is a circular route, you can start from various points. Good options for parking would be in the towns of Argoños or Ramales de la Victoria, which offer amenities and access to the route.

No specific cycling permits or entrance fees are generally required for this route, even when passing through natural parks like the Parque Natural de las Marismas de Santoña, Victoria y Joyel or the Collados de Asón Natural Park. However, always respect local regulations and protected areas.

The best time to cycle this route is typically during spring and autumn. These seasons offer more moderate temperatures and generally favorable weather conditions for challenging road cycling in Cantabria, avoiding the intense heat of summer or the colder, potentially wetter conditions of winter.

Yes, the route passes through sections of several other paths, including the [CIMA CA08] Asón - La Sía, Camino del Val del Asón (Nacimiento del río Asón), and the Ruta de Carlos V. You'll also briefly encounter parts of the Senda del Litoral.

This is a challenging racebike route, and bringing dogs along is generally not recommended due to the distance, elevation, and speed involved. While some areas might be accessible, it's not designed for cycling with pets.

Yes, the route passes through several towns and villages where you can find amenities. Argoños, Ramales de la Victoria, and Santoña are good places to look for cafes, restaurants, and accommodation options to refuel or stay overnight.

While the route is primarily for racebikes, some sections are noted as unpaved. These segments might be challenging or uncomfortable for standard road bike tires. It's advisable to check recent conditions or consider a bike with slightly wider tires if you're concerned, or be prepared to dismount and walk short sections if necessary.