Bug Light is really the Portland Breakwater Light, but everyone calls it Bug Light. It's on the tip of South Portland as you enter the harbor. It used to have a house attached to it for the keeper, so the lighthouse itself is tiny, and you access the top by means of two "staircases", known to most people as ladders. It's a tiny light as well, and the room gets pretty hot pretty quickly.
It is located right at the head of the harbor, so definitely had the best views of Portland, including the ginormous cruise ship that was in port yesterday (they just completed the mega-berth that allows those ships to dock. They used to have to anchor in the harbor and send everyone onshore by boat.)
Spring Point Light
Spring Point Light is also in South Portland, not far from Bug Light. What I didn't know before this visit is that it's a sector light - most of the windows are red. That means that ships coming into the channel keep a look out for when the light turns to white to see that they're aligned to the channel into the harbor. (We have a deep water port, but there's also a lot of rock out there - glacial drop zone and all - so staying in the deep water channel is very important.)
There was a ladder to get into the first floor of the lighthouse, but once you got there, it was stairs up to the rest of the floors. This light actually had living quarters (the breakwater only dates back to the 50s, so they used to have a row a boat out there), which was neat to explore.
Portland Head Light and Ram Island Light
Our final stop was Fort Williams Park in Cape Elizabeth. We stopped off for take out on the way and had a lovely lunch at the beach, and then walked up to Portland Head Light. We weren't able to get into the tower - the Coast Guard had given out limited tickets for that - but we were able to get into the museum for free, which was pretty cool.
The other lighthouse that we could see but not visit is Ram Island Light, which is right off the coast of Fort Williams. They actually recently auctioned Ram Island Light off, so it's now privately owned. You can see it quite nicely from the walking paths in the park.