The most notable feature of the Serbian-Hungarian border is a big fence -- 10 feet tall, 109 miles long and topped with razor wire -- which Hungary built to halt the migration through the country.
The Horgos camp is next to an official transit zone between Serbia and Hungary. It took about 20 minutes for reporters to cross into Serbia and about two hours to return, as Hungarian officials checked the trunk of most vehicles.
The dirt road to the Horgos camp stretches along the border.
Sayed Mohsen Shah, the elected leader of the Horgos camp, hands his portable battery pack to Serbian authorities each night. It's the only way he can make sure his phone gets charged, so that authorities can reach him.
As camp leader, Shah keeps the list showing when refugees will be allowed into Hungary. The country permits 15 people from the Horgos site and 15 from another border camp to cross the border each day. Some single men could end up waiting for two years.
A tent serves as a mosque. Most of the camp's inhabitants are Muslims from Afghanistan.
This summer, Serbian aid group Grupa 484 provided solar-powered lamps to the Horgos camp. That was after months without any light at night.
Refugees in the camp try to charge their phones through the solar lamps, but the lamps fizzle out by the time a phone's power hits just 10 percent.
One man tries to use a solar-charged lamp to power his phone.
Solar lamps sit outside nearly every tent.
Technology inside Horgos made a big leap last month after an aid organization jury-rigged a system of plastic pipes to turn the camp's single water spigot into five.
There are no showers. Instead, huts made of branches and blankets provide privacy as people hand bathe.
People living in the Horgos camp could soon get real showers -- if Hungarian officials and Serbia's Commissariat for Refugees permit them.
An Afghan family of five -- a husband, wife, her brother and the couple's two sons -- lives in this tent. If you look closely, you can see a teddy bear.
The family does everything near the tent, including cook over a campfire.
One of the boys in the family made himself a toy out of Band-Aids and old boxes, including one that once held a Sunlite solar lamp.
Kids play in the dirt along Hungary's massive border fence.
Inside this cluster of tents is the newest Horgos inhabitant, a week-old baby boy.
The newborn baby, named Omidullah, lies in a tent in the Horgos camp. Unlike in the US, babies born in European countries don't automatically become citizens.
Branches serve as clothes lines in Horgos.
Good grooming still matters in Horgos, and that includes haircuts.
Tents in Horgos are a variety of colors and patterns, all donated by different aid organizations.
An air conditioner juts out from the fence, caged in so refugees don't mess with the unit that cools Hungarian officers on the other side of the border.
Posters with photos and information help refugees find lost friends and family, including children. More than 10,000 refugee children are now missing across Europe, according to the European Union.
Some people in Horgos have dedicated solar chargers for their phones. The chargers are considered contraband by the Serbian and Hungarian governments.
Hungary's fence isn't built directly on the border. Instead, a pole marks where Serbia ends and Hungary begins. Hungary lets only 15 people through this gate each day.
The Horgos camp includes both families and single men.
People cover their tents with leafy branches as a way to control the temperature. It was hot when reporters visited in August, but colder weather will arrive soon.
The beauty of Budapest is a stark contrast to Horgos. Hungary's government -- and many of its citizens -- don't want refugees to settle in the country.
Many migrants bound for the EU end up in Serbia, blocked by Hungary's fence. Some hang out in Belgrade, the country's capital.
Many migrants live in Bristol Park, next to Belgrade's main bus station, where Serbs drag heavy luggage as they board coaches bound for vacation spots like Budapest and Croatia.
While the migrants living in Bristol Park have no tents, they do have free, Telenor-provided Wi-Fi. Migrants aren't allowed to cook, so Info Park -- a refugee aid center set up in Bristol Park -- distributes hot meals. The aid center opened last September on the day Hungary sealed its border.
Every so often, rumor comes that Hungary will open its border for a few days. The men living in Bristol Park quickly pack their belongings, sell or trash what they can't carry, and run for Horgos. But Hungary isn't opening its border anytime soon.
About 500 to 600 refugees, mostly single men, hang out in the center of Belgrade, waiting for a chance to sneak across the border or to be allowed to apply for asylum in Hungary.
Bristol Park: The first 270 in line get a meal -- like penne with tomato sauce and lettuce/tomato salad -- distributed promptly at 5:30 p.m.
Aid workers say they like volunteering for Info Park because they can help as much or as little as they want. We saw volunteers from places like England, Spain and Croatia.
About a dozen men charge their phones from power strips connected to Info Park's no-frills office.
Refugees in Belgrade take advantage of Info Park's free charging to watch videos on their phones.
Info Park's hut is now at risk of being torn down. Three days after our visit, the aid group heard the Serbian government may eject them.
Serbia wants to clear the park of migrants and send them to a camp in Krnjaca, a suburb on the edge of Belgrade.
Migrants in Belgrade pass the time by playing games.
Serbian authorities fenced off Bristol Park's grassy areas. It's officially a project to reseed the lawn, but aid workers believe it's really to keep refugees away.
Trash and clothes draped on plastic fencing in Belgrade's Bristol Park.
Serbs pay little attention to the hundreds of refugees camping in the park, even next to a billboard about the crisis.
After dinner, the refugees gather in a big circle to listen to music and dance.
Some even take out their phones to -- what else? -- film the revelry.