Get round-trip flights on Southwest Airlines with rates from $114 on Airfarewatchdog. We found the lowest fares on flights between Boston and Atlanta. Flights from Atlanta to Detroit start at $188, and flights from Baltimore to Orlando start at $140. You can enter your own travel dates and locations to find fare prices on Airfarewatchdog. Some of these flights need to be booked at least 21 days in advance and require travel on specific days of the week. Prefer to book with the airline? There's a resort promotion going on at Southwest Vacations, too. Taxes, fees, and restrictions may apply.