First way: From lonely cave
In Lonely Cave, Look behind you. In the water, You'll see something. You might think it's a sun, But it's actually a portal to cape of distant worlds! Go through it, And you'll be in cape.
Second way: From fluorite plains
You'll see an island not too far away. You'll see something on there that looks a bit like a sun. It's actually a portal! Go through it, And you'll be in cape.