Boten (Lao: ບໍ່ເຕ່ນ, Chinese 磨丁) is on the Lao side of the border between Laos and China. You can cross the border on foot.
The timezone changes at this border. Going from Laos to China it becomes one hour later. Coming to Laos from China it becomes one hour earlier.
Arriving in Laos, the border officials might come up with any number of reasons to squeeze an extra dollar or two out of you.
A Lao visa on arrival costs about 30 US dollars, depending on which passport you carry. There is also an additional 2 US dollar fee for this service as noted on a large sign.
There is a large duty free shop with official money changer on the Lao side on the left before the customs and immigration area. The building has a sign saying it's open until 10.30pm, but it seems to close earlier. There are also black market money changers on the Chinese side.
If you cannot pay in US dollars you may be overcharged. In 2015, Hippietrail was told 250 yuan for the visa although the true exchange rate would be 205 yuan, but managed to haggle it down to 220 yuan.
On the Lao side there are a couple of supermarkets, restaurants, and street food. Prices are in Chinese yuan and are not inflated.
If you need to sleep here there are cheap hotels for 60 to 80 Chinese yuan. There is a former casino several large hotels in various stages of completion which have all been (semi) abandoned for a few years. It would not be hard to find a place in here to camp the night for free. Some parts of some of the buildings seem to be used for prostitution, gambling, etc. Try to stay safe if you decide to sleep in this area.