A 10-minute walk from where the shop-lined Market and Daniels streets intersect at lively Market Square, the AC Hotel Portsmouth Downtown/Waterfront was an ideal base for our weekend of exploring New Hampshire’s historic seacoast city. An outstanding in-house restaurant with lofty views of the harbor was the frosting on the cake.

The chic contemporary lobby commanded our attention from the moment we were welcomed inside by the uniformed valet. Finished in polished black marble and rich woods, the lobby is separated into reception, lounge and bar areas, each roomy and the latter with comfortable seating. In the lounge, flickering firelight from a large glassed-in fireplace plays against polished black of polished marble surroundings.

Our room upstairs was decorated in restful gray and natural tones, and furnished in understated elegance with a king-sized bed, a full sofa, a desk with two chairs, and ample luggage space on fixed bench. Although a place for both partners to open luggage should be a given in any hotel room, we are always surprised at how rare this is. Extra points for AC.

They ticked the boxes for our other frequent complaint, too, with plenty of reading lights. Two lamps on the desk, one over the sofa and good spotlights over the bed meant that we had choices, and each of us could read in bed without eyestrain. More points.

The refrigerator, coffee maker and darkening shades over the full wall of windows were welcome, too. Our room overlooked the city, those on the other side overlook river as it widens into Portsmouth harbor. But we had plenty of chance to watch the harbor that evening at dinner.

The hotel’s restaurant, The Rooftop at the Envio , is at the top of adjoining building. Indoor dining tables surround a central bar, and outside tables line balconies on two sides, one of them heated. Half-glass walls reveal full views of the Piscataqua bridges and the harbor, and we watched lights come on around the cove and bay. The early evening was chilly and foggy, but we were comfortably warm at our outside table.

The menu is not long, but offers a good variety. I zeroed in on the lobster roll, which I had not had during my previous five days on the Maine coast. To me, lobster roll is something you eat at picnic tables on a wharf overlooking little boats bobbing in a harbor, not in a restaurant. But there I was with the prospect of a lobster roll before I returned inland, so I ordered it.

The lobster roll presented to me was twice the size of any I had ever seen. A huge mound of knuckle and claw meat, large chunks with no shreds or scraps, hid the open roll. Perfectly cooked and ocean fresh, the lobster was enlivened at every second or third bite by a crunch of celery. Cut in tiny bits, it was used more as a seasoning than an ingredient.

The lobster was dressed with just enough mayo and a single lettuce leaf as a barrier between the lobster and the roll and garnished simply with lemon slices and crisp pickled green beans. The mound of crisp French fries was superfluous with all that lobster, but they were delicious, so I ate some anyway. Had I known how big the lobster roll would be, I would have opted for sharing the appetizer of plump mussels.

My companion ordered the New England style braised beef short rib, which was served with Parmesan potato gratin, roasted purple carrots and broccolini. Equally delicious – and bountiful. We finished with a shared bowl of raspberry sorbet, served with five macarons. By then, darkness had fallen and we watched as the fog drifted in wisps, obscuring bits of harbor lights, then moving on to form a shifting mosaic of lights and mist.