Maine’s largest city will kick off its annual celebration of its waterfront with the 41st Old Port Festival.

The festival begins with an art walk at 5 p.m. on Friday and will also include two presentations of the Circus Conservatory of America’s “Circus in the Square” at Monument Square at 5 p.m. and 7 p.m. There will also be street performers and artists along Congress Street.

The festival expands from one day to three days this year. Saturday’s events include a downtown scavenger hunt and “Circus in the Park” at Lincoln Park. Sunday, the main day, includes the Old Port Festival Kick Off Parade, amusement rides, and live music.