Finding out how much a property sold for, which lots it touched or what zoning district it was in, used to require a visit to City Hall. But a new online portal makes that information and much more directly available online through the city's website.

The feature uses the map-based platform MapGeo and incorporates layers of data built by city staff and the Federal Emergency Management Agency in user-friendly overlays. With topographic contours, water navigation maps and a trove of property data, the portal offers a powerful tool for residents and property owners, and presents a rabbit hole for the curious.

City Planner Wayne Marshall said the new feature has been on the website for several months but was "limping" until recently when Assessor Brent Martin added property tax data.

"We're really excited," Marshall said. "Our intent is to make everyone aware of what we have."

Clicking on a property reveals information from tax cards kept at the City Assessor's Office, including some old photos and floor plans. Online, these images are still hit-or-miss, but the occasional hit — a snapshot of Shop & Save (now Hannaford) or a floor plan for the old Penobscot Frozen Foods plant (now Penobscot McCrum) — rewards the patient user.

To view the the new maps, visit and click the "Aerial Maps & Property Data" link under the Assessor or Planning & Codes department pages.