The battle between tech titan Vinod Khosla and California activists is heating up.

This week, Khosla filed an appeal with the US Supreme Court to overturn a 2017 ruling that forced him to open public access to a California beach that surrounds his shorefront property.

In 2008, Khosla — who made his fortune as an investor and one of the co-founders of Sun Microsystems — paid a reported $37 million for an 89-acre parcel near Half Moon Bay, about an hour south of San Francisco. For many decades, surfers and families had enjoyed the beach, which is known for its stunning geological formations, picnic areas, and ideal surfing waves.

When Khosla closed the gate to Martins Beach in 2010, locals revolted. A California appeals court later ruled that Khosla violated state law when he blocked the public from accessing the beach and forced him to reopen it. Now he's taking his case to the nation's highest court.

Here's what we know about Martins Beach.