You can stop off , for example , at historic Fells Point , Baltimore 's first seaport -LRB- there 's a Maggie Moos ice cream shop across from the stop -RRB- or at the star-shaped Fort McHenry National Monument -LRB- 410-962-4290 ; www.nps.gov/fomc ; admission $ 5 , free for ages 15 and under -RRB- ; in 1814 , Francis Scott Key composed the '' Star-Spangled Banner '' while observing the British naval bombardment of the fort .