Complex sentence: Dating to 1600 BC, the site was discovered by Peruvian archaeologist Julio C. Tello in 1937 who believed it was the capital of an entire culture, now known as the Sechín Culture.
Split into simpler sentences: Dating to 1600 BC, the site was discovered by Peruvian archaeologist Julio C. Tello in 1937. He believed it was the capital of an entire culture, now known as the Sechín Culture.