Dating back to Roman times, Leadenhall Market’s stunning architecture has been featured in movies ranging from Harry Potter to Lara Croft: Tomb Raider. Highlights include a Roman mosaic, the burial spot of legendary goose Old Tom, and a wealth of boutique stores and restaurants serving everything from fine wines and British cheese boards to Argentine steak and Mexican tacos. Visit the filming location of the Leaky Cauldron pub and see more film settings on a Harry Potter tour.

Just across the water from HMS Belfast is St. Dunstan in the East Church Garden, a secret garden in the heart of London. Christopher Wren, the architect responsible for St. Paul’s Cathedral and Kensington Palace, designed the church, but after the Blitz bombings, nature took over. Today, vines and branches wind themselves around the historic walls, and light pours through the paneless windows, making this unexplored historical attraction in London a photographer’s dream.

All Hallows By The Tower Church is the oldest church in London—it boasts 1,300 years of history and is still standing after damage during the Great Fire of London and World War II. Walking tours focused on London’s Roman history include the church and significant nearby landmarks, such as the London Wall and Guildhall, and the church offers free guided tours on most weekdays. The Crypt Museum beneath the church features Roman and Saxon artifacts, ancient registers, and a Roman tessellated floor.

On a side street off a busy stretch of road between Boxpark Shoreditch and Liverpool Street station sits Dennis Severs' House, a townhouse built in 1724 for a wealthy family of silk weavers. Brought back from the brink of dereliction, the house now recreates the daily life of the people who once lived there; each room is designed to feel like someone has just departed from it, and the paintings, upholstery, and decor of each room are modeled on different historical periods.

Tucked away near some of the capital’s most recognizable landmarks is one of the lesser-known historical venues in London. In Victoria Tower Gardens on the banks of the Thames River, you’ll find the Buxton Memorial Fountain, a 19th-century water fountain erected to celebrate the abolition of slavery. Bright mosaics depicting fables and scenes of emancipation cover the fountain. It is also the ideal place to snap crowd-free photos of the back of the Houses of Parliament.

Just outside of Tower Hill Station, you'll stumble across one of the last remaining sections of the London Wall, a piece of original Roman architecture used to defend and demarcate the boundaries of Roman Britain's capital, dating all the way back to 200 AD. Historical walking tours take you right back to Roman times, covering the London Wall, London's Roman Amphitheater, and the Tomb of the Unknown Roman Girl.

Home to more than 50,000 living plants, Kew Gardens spreads across 326 acres (121 hectares). While it might be best known for its horticulture, going back more than 250 years to when British royalty founded it, the UNESCO World Heritage site's far-flung location makes it often overlooked. Highlights include a carnivorous plants section, a rose garden with hundreds of blooms, an arboretum home to 14,000 trees, and King William’s Temple, built in 1837 in homage to Queen Victoria.

Just a short train ride from London Waterloo, this 18th-century castle was the brainchild of Horace Walpole, who wrote what has been hailed as the world’s first Gothic novel. Highlights include rich, red-wine-colored walls beneath dramatically vaulted ceilings; stained glass windows; wooden Georgian features; manicured gardens; and bone-white Gothic turrets. This fairy-tale palace brought to life is the perfect place to enjoy afternoon tea in the Garden Café.

Completing London’s quartet of UNESCO World Heritage sites is Maritime Greenwich, a cluster of underrated historic London landmarks. See the original tik-tok at the Royal Observatory, home to the famous Harrison’s Clocks, and admire the Painted Hall in the Royal Naval College, nicknamed England’s answer to the Sistine Chapel—book your tickets in advance to sail past lines on the day. The parks surrounding the buildings are also a lovely spot for a picnic on a sunny day.