Mirador Laikakota is a park located atop a hill in the middle of the valley the city of La Paz occupies, just a few blocks away from the H. Siles soccer stadium in Miraflores. This is basically a long, narrow hill that runs along the interior of the valley separating downtown La Paz and Sopocachi from the Miraflores neighborhood. The park runs along the length of the hill and has a series of playgrounds.
What's beautiful about Mirador Laikakota is that you have practically a 360-degree view of the city. On a beautiful sunny day you can take absolutely stunning photos of the city all around you. The view of downtown La Paz is especially breathtaking because it is so nearby. Toward the southern end of the city you'll see the Muela del Diablo (a molar-shaped mountain top far in the distance and to it's left, the impressive Illimani mountain La Paz is so famous for. Illimani tends to have it's own personal weather system and is often clouded over and completely invisible even when the weather is great elsewhere in the city, so the chance to take photos of it from the top of Mirador Laikakota is a real treat.
Today there are a series of long, wooden boardwalks that wind down into the city (downtown area toward Sopocachi) but only a few years ago it was just a little park almost no foreigners knew about. (I found some old photos - only about 10 years old - and thought you might like to see what Laikakota and La Paz looked like before this overlook became known to tourists. When I was little, and living in Miraflores, there was no park at the top at all.)
The Mirador de Laikakota is, in my opinion, the absolutely best place to take photos in La Paz.