Balboa Park is the largest urban park in the country. In addition to museums and cultural attractions, the park is home to over 40 hiking and biking trails, walks, and gardens. While gardens might not technically be considered hikes, they are worth mentioning among outdoor places to walk with scenic views.
The Desert Garden covers 2 acres of the park, making it a short walk. This is ideal when you want to experience nature but are short on time. This and many of the other gardens in the park, would make great lunch spots if you work in the area.
If you have more time and are taking a tour of the park, the Desert Garden is in the middle of the park near the Rose Garden and museums. The garden has over 1,300 plants from around the world. Peak blooming time is from January - March, so now would be a perfect time to visit. However because of the variety of unusual and interesting plants, the garden is beautiful anytime of year.