The Huaca del Sol is a massive adobe brick pyramid built by the ancient Moche civilization in Peru. It's a huge structure made of over 130 million bricks. Archaeologists think it was used for sun rituals, ceremonies, and even a royal residence back in the day. But sadly, a lot of it got messed up by looting and erosion over time. So now, only about a third of it is left standing.

These ruins are a bit further away from Huanchaco (they are in Trujillo) so if you are short on time I would opt for Chan Chan.