A little known local secret; after being closed for years, the Old Post Office Tower is open again for (almost) daily tours from 9 a.m. to 5 p.m. From an observation tower 270 ft. above the city, guests can view the famous landmarks of Pennsylvania Ave. including the White House, the Capitol, the Washington Monument and, on a clear day, as far as the Pentagon. The tower is free to visit and does not require advanced tickets.

A unique treat for Oscar the Grouch-types, the corpse flower is a rare-blooming plant at the U.S. Botanic Garden that, when open, gives off the stench of rotting garbage. So far, it has bloomed twice this year. The flower stays open for a short window (2-3 days), so you need to make a b-line to the garden when this hidden gem is revealed.

You'll find a literal hidden gem within this museum! Head to the Schwarzman Family Library on the second floor where a secret door reveals a hidden screening room (or a secret hideout. You decide!). This magical library is a treasure trove of surprises. You'll also find a number of hidden dioramas of famous books that can only be revealed when you read a passage from the book aloud in front of the secret picture frames.

If you haven't heard, Georgetown's has a new attraction and it will take you back in time! After more than a decade, canal rides are back in Georgetown whisking visitors along the historic transportation route envisioned by George Washington. Tours are available five days f a week from TK to TK during the inaugural season. This boat is a near-exact replica of an 1880 boat with one important distinction: this one has a modern bathroom!

If you have a little gamer, introduce them to the original console, the pinball machine. Mom's founder Scott Nash has shared his personal collection of pinball machines in an arcade lounge at the College Park grocery store. You'll find almost 30 restored classics like "Flash Gordon" alongside newer models, like "The Simpsons." There is an onsite change-making machine and a seating area for those that just want to cheer from the sidelines.

Anderson House was built in the spring of 1905 as the stateside home of American diplomat Lars Anderson and his wife, Isabel. Today, the 50-room mansion on Embassy Row is a museum and library featuring most of the original furniture and artwork. You’ll learn about the significance of the American Revolution while touring this historic property. Docent-led tours are available Tues.-Sun. and last about an hour. Admission to this stately home is free.

Watching the sun set over our nation's capital is a must-do at least once. There are a number of pricey restaurants and rooftop bars where you can pay handsomely for the view or you can head over to the Kennedy Center where the rooftop is open to the public and allows outside food. Family picnic, anyone?

Pint-size aviation buffs will love hanging out at Gravelly Point Park, which is conveniently situated just off of the George Washington Parkway. It's there where they're able to watch planes take off (right above their heads!) from Reagan National Airport. Pack a picnic or bring popcorn to make plane watching a serious spectator sport.

This secret hideaway on the Capitol Grounds was designed by landscape architect Frederick Law Olmsted in the late 1800s to create a much-needed space for visitors to sit and rest. Inside this open-air building you can still enjoy a break from the elements on the shaded benches or refill your water bottle at one of the three drinking fountains. Summerhouse is a great place to play a quick game of hide-and-seek on your way to a near-by tour or activity.

This one-time battlefield is now an oasis of peace in the middle of urban bustle. Rich with history, it even includes a plaque to commemorate the spot where President Lincoln stood and came under enemy fire. It’s a beautiful place for a picnic and a couple of hours of learning and play. Make sure you check out the cannons, ramparts, and moat before you leave. The park is open every day from sunrise to sunset.

The Heurich House Museum only offers tours for ages 10 & up, but you can still take your younger explorers to the Castle Garden (the public entrance is in the back). This secret garden is the perfect place for a picnic or spend an hour or two on a bench with a good book in the shadow of the castle. There is no fee to enjoy the grounds which is open to the public Mon.-Fri. from 11 a.m.-5 p.m.

"Clang, clang, clang went the trolley." Does your little one like to ring the bell? The National Capital Trolley Museum is a must-do day trip into a bygone era of transportation. Hop aboard a street car for a quick journey into the woods or enjoy a tour on an authentic tram. You can also explore the barn that houses several restored trollies. Admission includes the museum displays, a docent-led tour, and unlimited trolley rides.

You don't need to be a Harry Potter fan to enjoy this small museum filled with antique vials and mysterious glass bottles.  You'll find an authentically-restored 18th century apothecary on the first floor, but the real fun is upstairs where little drawers hold a treasure-trove of seeds, plants, and other goodies displayed  exactly as they were when the apothecary was in full operation. Tours are available on the half-hour every Sun. and Mon.

Pose next to the beloved Smokey Bear, the poster animal for preventing forest fires, at the National Zoo. Along the commemorative trail, you will also see reproductions of vintage Smokey Bear posters and photos of the real Smokey Bear that once called this zoo home. Want to learn more about preventing forest fires? Check out smokeybear.com where kids can print out hands-on activities.