Fill a large pot with water and bring it to a boil.
Add Old Bay seasoning and salt to the boiling water.
Add baby potatoes and cook for 10 minutes.
Add corn and cook for an additional 5 minutes.
Add crab legs and cook for 5 minutes.
Add shrimp and mussels, cooking for another 5-7 minutes.
Check that shrimp are pink and mussels have opened.
Drain the pot, reserving a bit of the broth.
Spread the seafood and vegetables on a large platter.
Drizzle melted butter over the top and garnish with lemon wedges.