Doors Open Toronto, the annual peek inside some of the city's most interesting and hard to access buildings, returns for its 15th year on May 24 and 25, 2014. With over 40 new places to explore and a host of old favourites back on tap, the roster is as strong as it's been in the last few years. If you've been hitting up Doors Open for a while, it's these new buildings that will hold the most interest for you as you plan this year's visit.

While places like the the R.C. Harris Water Treatment Plant, Osgoode Hall and the Royal Alexandra Theatre are all fascinating to get a behind the scenes look at, they're a part of the program year in and year out, and many participants have already seen them. Throw in the fact that these are typically lineup-heavy destinations, and there's more and more reason to tailor your travels around the latest offerings.

Here's a roundup of the best of Doors Open Toronto 2014, with a focus on newly added buildings.

Artscape Youngplace
The newest addition to Artscape's stable of properties, the $17 million transformation of what was once the Shaw Street School into a community arts hub is rather remarkable (we got a tour when it first opened) and a rather perfect example of how to do adaptive reuse projects. Guided tours are the best way to go here, as you'll get a chance to check out some of the hidden spaces in the building and get a quick lesson on the site's history.

High Level Pumping Station
Probably the building I'm most excited to visit this year, the High Level Pumping Station was long overdue for inclusion in Doors Open. While the deco elegance of the R.C. Harris Water Treatment Plant will still draw droves of visitors, this water facility, which still pumps water to higher elevations in Toronto, is every bit as fascinating. Hardcore photographers will be pleased to know that they can use a tripod during their visit.

Pachter Hall and Moose Factory
Quite possibly one of the coolest houses in Toronto, artist Charles Patcher's residence and studio is often open for private art events, but this is the first time that it makes a Doors Open appearance. Located among the predominantly early 20th century homes on Grange Avenue near the AGO, this hyper modern building designed by Steven Teeple & Associates is a stunning example of contemporary architecture and the potential of small sites for urban renewal. Tours are planned each day.

TTC Russell Carhouse
The TTC typically makes one or two of its facilities available for Doors Open, which is a boon for transit nerds everywhere. This year we get a look inside the Russell Carhouse, where many streetcars are repaired. As an added bonus, a new low floor streetcar will be on hand for boarding, along with older models like the PCC and Peter Witt.

The Bank of Upper Canada
If old buildings are your thing, this is one to have on your list. Built in 1834, this former bank on Adelaide between Jarvis and Sherbourne offers Doors Open visitors a chance to get a look at the inside of this Neo-Classical building and National Historic Site. It's a short tour, but one that will appeal to those curious about Toronto's oldest architecture.

The Great Hall
You've probably already been to the Great Hall for a concert or two, but here's a chance to see some of the areas not normally accessible to the public like backstage, the basement theatre area, and the renovations taking place on the ground floor. If ghost stories are your thing, there will be a few of those too.

The Theatre Centre
Formerly a Carnegie library and a Canada Post office, The Theatre Centre is a welcome heritage conversion in condo-rich West Queen West. Having just opened in March, this Doors Open appearance should serve as a good first chance to check out the adapted space, which houses a 200 seat theatre as well as studio and gallery space. Making things even more interesting is that Mammalian Diving Reflex will be in the midst of setting up a new performance on the weekend.

Fort York Armoury
I've wanted to get inside this hanger-like building for quite some time, so it's exciting to see it finally get the Doors Open treatment. Still used by the Canadian Forces, this building looks a little like it could be an arena or basketball court at first glance. This will be a good one for architecture photographers, who will no doubt be taken with the roof of the building.

Gibraltar Point Lighthouse
One of Toronto's oldest structures, and the site of the city's best known ghost story, this lighthouse probably only makes sense to visit if you're already heading to the Islands on the weekend. When here you can decide whether or not to skip over the 13th step, which some have said is where keep J. P. Rademuller was murdered way back in 1815.

Knox College
Here's a place on U of T's campus that you probably haven't seen before, complete with a Wolff organ and one very picturesque library. This is about as pretty as gothic-style academic architecture gets, and could be a good place to take a break during a hectic day of touring other buildings.

For a full list of Doors Open buildings, check out the official website.

CONTEST

Submit your photos of this year's Doors Open Toronto for a chance to win a $500 gift certificate from Henry's Canada. Just upload your photos to the blogTO Flickr pool and tag them with #blogtoDOT14. Submission deadline is midnight on May 25th. Starting May 26th and running through June 1st we'll showcase 10 finalists where a reader vote will decide the top three. Prizes include:

• 1st place: $500 gift certificate to Henry's Canada.
• 2nd place: $100 gift certificate to Henry's Canada.
• 3rd place: $50 gift certificate to Henry's Canada.

Note: all photos must be of a 2014 Doors Open Toronto 2014 venue and taken on May 24th or 25th, 2014.