Fill a large pot with water and bring it to a boil. Add salt, Old Bay seasoning, and lemon juice.

Add the baby potatoes and cook for about 10 minutes.

Add the corn, onion, and garlic, and cook for another 5 minutes.

Add the shrimp, crab legs, and mussels to the pot. Cook for an additional 5-7 minutes, or until the shrimp are pink and the mussels have opened.

Turn off the heat and let the seafood sit for a few minutes to absorb the flavors.

Carefully drain the pot using a colander and transfer the seafood and vegetables to a serving platter.

Serve hot with extra lemon wedges and melted butter on the side.