San Borja is a city in Beni in Bolivia.
From a tourist point of view San Borja is nothing special apart from a necessary stopover on the way to San Ignacio de Moxos or Trinidad. However, the town has seen a large influx of people in the last 50 year, multiplying the local population by over 5 times.
From Rurrenabaque, take two shared taxis to San Borja, changing in Yucumo. Each leg is around 2 hr and cost around Bs. 70-80 each way. You can get a shared taxi directly from Rurrenabaque (via Yucumo) for Bs. 80; takes 2h 30 min. Rurrenabaque to Yucumo is asphalt (with holes), and Yucumo to San Borja is an impressive dirt road.
Otherwise, frequent buses travel between Rurrenabaque and La Paz. Get off in Yucumo and take another one from there.
An alternate way would be to fly into Trinidad and carry on by land.
The bus (and shared taxi) terminal is at the edge of the town. Take a mototaxi to travel between the two.
Moto taxis (motorcycles) or the occasional real taxi.
Central square has elements painted yellow with red, which makes for a warm and positive impression.
Locals spend weekends out of town (possibly in the nature) - ask them where and how.
There are some stalls in bus terminal that sell basic food and drink.
Some say straying more than a few blocks from the main plaza at night is dangerous.
Internet is generally slow and on slow machines that cost Bs. 10/hr. Telephone calls to the U.S. are a bit steep.
Primary administrative division