Hailed as San Francisco's real 'crookedest' street, Vermont Street is a hidden gem often overshadowed by Lombard Street. Tucked away between 20th and 22nd Streets in the Potrero Hill neighborhood, this winding road is full of hairpin turns and switchbacks. Unlike Lombard, Vermont Street doesn't see many tourists, so walking paths are limited. However, ask any tour guide and they'll confirm Vermont is indeed, the 'crookedest' street, making it a San Francisco must see!

This picturesque stretch of Lombard Street has eight tight turns on a single block. They twist at very acute angles, making for very slow going if you are in a car. Although, oddly enough, cars were the reason for designing the street this way back in 1922. The idea was that this design would make it easier for them to negotiate the steep 16% grade. The drive is usually bumper-to-bumper and in the summertime, there is almost always a line of cars waiting to take the drive down. That being said, going for a stroll along this landmark is a good option, especially when the hydrangeas along the sidewalk are in bloom.

Cupid's Span is located on the waterfront near the Bay Bridge in the magnificent Rincon Park on the Embarcadero. The structure is 60 feet high and is made up of painted fiber glass and stainless steel. Designed by two Swedish artists, Claes Oldenburg and Coosje Van Bruggen, this eye-catchy piece of work is a major attraction in the park.

Wild sea lions have flocked to Pier 39 since the 1989 earthquake and the population has grown ever since. Every winter the number increases to almost 900, thanks to the availability of space and ample food. Although some of the sea lions choose to migrate seasonally, usually some still keep Pier 39 as their regular haunt. You can bring your kids over for free educational talks by the Marine Mammal Center, held on weekends year-round provided the weather is good. See these wild adorable creatures up close and personal at this family friendly spot.

This piece of artwork in the Marina also plays music. The sea-powered organ is a set of pipes that run along the waterfront and extend into the waters of the bay. The organ was built by scientists from the San Francisco Exploratorium. Place your ear against one of the pipes and listen to the music created by the sound of the waves. It's a unique way to enjoy nature and this is, perhaps, one of the few places in the world that you can.

Situated along John F. Kennedy Drive and a part of the magnificent Golden Gate Park, the Bison Paddock is just like it's name suggests; it's a large enclosure of a herd of bison where visitors can come to admire these large animals. Buffalo have been in the park since 1892, since the city kept unique animals in Golden Gate Park before the city's zoo opened.

The Ingleside Terraces Sundial is one of the most unique spots to visit in San Francisco. This sundial was greeted by 1500 people when it was inaugurated on 10th October, 1913. The 28 foot monument is created out of marble and concrete. There are also many events hosted at the Ingleside Terraces park with the sundial taking the center. The attractive architecture sure invites many tourists as well as locals for its magnificent sight.

Sutro Baths was built in the late 19th Century. It was a large swimming pool owned privately by Adolp Sutro, who was a former mayor of San Francisco. It had seven different pools, one having fresh water and the others having salt water, but varying in temperatures. Below the Cliff House, a small beach inlet was filled almost hiding the vast iron, glass and concrete structure. The bath had a high operating cost, due to which it eventually closed and a fire in 1966 almost destroyed it leaving behind the ruins. The ruins of the Sutro Baths are open to the visitors as well as the cave where you can catch a glimpse of bats.

The Golden Gate Park windmill is located close to the Pacific Ocean and is ideally suited to use the strong ocean winds. Standing 75 feet tall the windmill was used to pump well water for irrigation purpose. The Queens Wilhelmina Tulip Gardens that surround the windmill adds to the beauty of the Golden Gate Park. It also makes it the most picturesque spot in the park and is also referred to as the North Windmill.

This San Francisco landmark was built to resemble a vintage camera, but the origins of the camera obscura are far older than modern photography. Leonardo da Vinci outlined the principles governing it in the 16th Century. You enter a darkened, hushed room where the walls are lined in black velvet and holograms. In the center is a bowl-shaped screen, 3 1/2 feet in diameter. Using mirrors and lenses, a living image of the surrounding ocean and beach are projected onto the screen. The difference between seeing that scene outside or seeing it on the camera obscura is the difference between reality and a dream.

This 92-foot (28 meters) tall sculpture is one of the largest aeolian harps in the world. This instrument, known to be played by the wind movement, was created by Lucia and Aristides Demetrios. Made of steel, the sculpture is 243 feet (74 meters) high and offers beautiful views of South San Francisco Bay and can be viewed from the city's airport and the East Bay. Visitors can come here on a windy day to listen to the sounds of the harp.