Brown, Yale, Columbia, Univ of Penn, Princeton, Harvard, University of Chicago. OK, not technically LACs, but they are the (undergrad) size you want and are urban or, in the case of Princeton, close to big urban areas.
New College of Florida (Sarasota).
Lewis & Clark (Portland, OR)
Vassar (in Poughkeepsie, if that’s a big enough city for you. Two hours from NYC.)
Kalamazoo College.
Clark University and Holy Cross are in Worcester, MA.
Reed College (Portland, OR)
Drew University (Madison, NJ – 45 minutes from Manhattan)