Maryland hotels with 18+ check-in
At 18 you can hit a wall at certain hotels, the ones that will not check in anyone younger than 21. That worry doesn't have to follow you into Maryland, because the city this page covers has hotels that allow 18-year-olds. Your search just got shorter, since where in Maryland to look is already off your plate.
Hotel list coming soon
Baltimore
A Maryland trip built around the National Aquarium
The city this page covers is Baltimore, where the National Aquarium sits downtown on the Inner Harbor. If the aquarium is what you are coming to Maryland for, that trip happens in Baltimore.
Baltimore also has hotels that check guests in starting at 18, which puts the reason to go and the room in the same city. That is what this page covers, and all it covers.
Maryland has an airport with its own rail station
That airport is Baltimore/Washington International Thurgood Marshall Airport, BWI Marshall for short, and it sits 9 miles south of downtown Baltimore. The other city in its name is 32 miles the other way, so the long name is not a sign that you will land far from the city you are booking.
The airport has its own rail stop, BWI Marshall Rail Station, and the shuttle between the terminal and that station is free, which is the right price when the whole trip is coming out of your own pocket.
That station is a stop on MARC's Penn Line. In Baltimore itself, you can board MARC trains at Penn Station, and Penn Station also sits on Amtrak's Northeast Corridor. If no one on the trip is driving, keep those two stations in mind, one at the airport and one in the city where you are booking the room.