Dumbarton Oaks. Image by the author.

Formal gardens are carefully manicured, clearly man-made park spaces. They don't make any attempt to mimic nature, and they're not home to ballfields or blacktops. Instead, they're strolling spaces designed specifically to appeal to humans' sense of beauty. The Washington region is blessed with some of the best formal gardens in North America. Here are 12 of them.

1. Franciscan Monsastery

Brookland's Franciscan Monastery is a soaring cathedral-like building, with a lovely colonnade-enclosed garden in the front. Its rarely-crowded rose-lined walkways are ideal for a quiet contemplative stroll.

Franciscan Monastery. Image by the author.

2. Brookside Gardens

This Montgomery County public park near Wheaton surely has the best tulip collection in the Washington area.

Brookside Gardens. Image by the author.

3. Bishop's Garden at National Cathedral

Most visitors to National Cathedral focus on the building itself, and for good reason. But the grounds are a delight too, in particular Bishop's Garden. It was designed by the famed Frederick Law Olmsted Jr., but in a much more formal style than the usual idealized-nature Olmstedian fare.

Bishop's Garden. Image by the author.

4. Hillwood Estate

The former home of Marjorie Merriweather Post is now a decorative arts museum, with fabulous gardens that feel like a slice of Europe. Unlike most other gardens on this list, Hillwood does require an entry fee.

Hillwood Garden. Image by DC Gardens licensed under Creative Commons.

5. US Botanic Garden grounds

The main event at the US Botanic Garden is the greenhouse conservatory building, but the grounds offer a mix of formal and informal outdoor gardens too. Don't miss the Bartholdi Fountain, across the street south of Independence Avenue.

Botanic Garden grounds. Image by DC Gardens.

6. National Arboretum Herb Garden

The US National Arboretum is a sprawling naturalist park, famous for its informal wooded groves and its stand of US Capitol columns. It does have a small formal herb garden, near the main R Street entrance.

National Arboretum Herb Garden. Image by the author.

7. Mount Vernon's Upper Garden

George Washington's historic plantation has two main gardens. The Lower Garden is dedicated to growing food, while the Upper Garden is more decorative. You will have to buy a ticket to get in.

Mount Vernon Upper Garden. Image by Craig Fildes licensed under Creative Commons.

8. Haupt Garden at the Smithsonian Castle

This garden on the Independence Avenue side of Smithsonian Castle is by far the most ornately landscaped part of the National Mall. Thank goodness cooler heads prevailed over a proposal to bulldoze it.

Smithsonian Castle garden. Image by the author.

9. Tudor Place

This oft-overlooked corner of Georgetown is an easy and wonderful respite from the bustle of Wisconsin Avenue.

Tudor Place garden. Image by DC Gardens licensed under Creative Commons.

10. Oatlands Plantation garden

Way outside the Beltway, beyond Dulles Airport, Oatlands Plantation is a manor house with an attached garden. Visitors must pay to enter.

Oatlands Plantation garden. Image by lcm1863 licensed under Creative Commons.

11. Bon Air Park Rose Garden

Arlington's only formal garden is about a mile west of Ballston, next to Four Mile Run.

Bon Air Rose Garden. Image by the author.

12. Dumbarton Oaks

For a spot that's frequently cited along Versailles on short-lists of best gardens in the entire world, shockingly few Washingtonians even know Dumbarton Oaks exists, much less have visited it. This breathtaking garden where Georgetown backs up against Rock Creek Park is an absolute must-see that's well worth the limited hours and entry fee.

Dumbarton Oaks. Image by the author.

While it may be true that as spring becomes summer, peak flower-blooming season is behind us, these gardens are all still marvelous places to stroll. What's your favorite? And did I miss any other good ones locally?

Dan Malouff is a transportation planner for Arlington and an adjunct professor at George Washington University. He has a degree in urban planning from the University of Colorado and lives in Trinidad, DC. He runs BeyondDC and contributes to the Washington Post. Dan blogs to express personal views, and does not take part in GGWash's political endorsement decisions.