Arrive around noon and begin at Market Square, the heart of downtown Portsmouth. Spend about an hour wandering the brick sidewalks around Market Street, Congress Street, and Bow Street, ducking into independent shops and admiring the historic brick buildings. Downtown is very walkable, but parking fills quickly in summer; the Foundry Place Garage is a convenient choice, while metered street parking is useful for shorter stops. Most shops generally open by 10 a.m. or 11 a.m., though individual hours vary.
For lunch, walk a few minutes to The Friendly Toast for creative comfort food, breakfast-all-day plates, sandwiches, and fun cocktails or coffee. Plan on roughly $15–25 per person and expect a possible wait at peak lunchtime; putting your name down and browsing nearby shops is easy. Afterward, settle in at Portsmouth Book & Bar, a distinctive literary café-bar where you can browse used books and have a drink in a relaxed setting. Allow about 45 minutes, and check its current hours before heading over since daytime and evening schedules can vary.
From downtown, Prescott Park is an easy 10-minute walk south along the waterfront, or a very short drive if you prefer to save your energy. Give yourself an hour to an hour and a half for the formal gardens, shaded paths, lawns, and views across the Piscataqua River. The adjoining Strawbery Banke area adds some lovely historic streets for a brief wander, even if you are not visiting the museum. Gardens and park grounds are generally free, though special events may charge admission; bring water, sunscreen, and comfortable shoes.
If schedules line up, board The Gundalow Company from the Prescott Park waterfront for an evening harbor cruise. These usually run about 1½ hours and cost approximately $40–55 per person; reserve ahead because summer sailings can sell out, and arrive 20–30 minutes early. If no cruise is operating, stay in Prescott Park for sunset—the river light and working harbor views are especially good from the waterfront promenade. Finish with dinner at The Black Trumpet, a short walk away in the South End, for seasonal, globally inspired food in a cozy setting; budget about $35–60 per person and make a reservation if possible. Since you are checking in late, confirm the hotel’s after-hours arrival procedure before dinner, then walk or drive over afterward rather than trying to squeeze in another stop.