Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is the first in the series of movies about Indiana Jones, the world's worst archeologist. He usually steals some priceless treasure from an ancient temple, and then destroys the temple. And he often encounters snakes.
In the opening sequence of the film, Indiana (Harrison Ford) steals a golden idol from a temple and then is chased by South American savages shooting arrows at him. He jumps into a getaway plane that takes off from a river. Just as it gets airborn, Jones is startled to see a large python on his lap and yells to the pilot who tells him it's just his pet snake Reggie. Then we get the classic Indiana Jones soundbite as he screams "I hate snakes, Jock, I hate 'em!" With a setup like this, you know there will be more snakes in this movie, and there certainly are.
The snake in the scene is a Burmese Python, which is found in Asia not South America, but since it's a pet, it's not necessarily a local snake. Later in the movie we see Boa Constrictors in Egypt, which are from the Americas, not Africa, which is a mistake, but one that most of the audience wouldn't know or care about.
Jones is hired by Army intelligence to find the Ark of the Covenant before the Nazis do. It was established early in this film that Indiana is afraid of snakes, so when he learns the location of the Ark, it's not surprising to find out that it's hidden in a temple called The Well of Souls that is absolutely filled with snakes. There are snakes all over every floor, snakes crawling out of holes in the wall, and snakes crawling through skulls. Even the decorations and statues in the temple depict snakes. Looking down into the temple full of snakes all Indy can say is "Snakes, why did it have to be snakes?" His assistant Sallah says "Asps. very dangerous. You go first."
Jones climbs down a rope to the floor of the temple, where he barely avoids a deadly cobra. Then he sprays gasoline onto the snakes and sets them on fire. Later when he returns to the same spot it's full of snakes again. So much for the fire. Where did he get that gasoline, anyway?
After he finds the Ark, which someone describes as a radio for speaking to God, his men hoist it out of the temple just as the bad guys show up. They throw Indiana's girlfriend Marion (Karen Allen) down with him. After he hands her a torch, telling her to wave it at anything that slithers, she mistakes his bullwhip hanging from his waist for a snake and tries to burn it, giving us a good laugh. Then we see lots and lots more snakes, including the obligatory shot of a snake crawling out of a skull. The two manage to escape the snake pit quickly, after seeing snakes coming out of holes in the wall give Indy an idea how to escape.
The snakes used in the temple are a combination of fake rubber or plastic snakes and live snakes along with some live legless lizards, possibly Slow Worms, that look like snakes, but are actually lizards. They also used live boa constrictors and pythons and a few cobras.
The large number of snakes in the temple forces me to ask - why are they all hanging around there? Don't they need food and water and sunshine and mates, etc., all the things live snakes need? And why aren't they quickly trying to get out of the open and hide the way snakes always do? The only explanation that makes sense is that they were somehow magically enchanted by whoever left them there to guard the Ark centuries ago. If you can buy the idea of the awesome destructive powers of the Ark, it's not much of a stretch to believe in enchanted snakes.
In a June 12, 2021 interview with Antonio Ferme for Variety Magazine, commemorating the 40th anniversary of the June 12, 1981 release of the movie, Karen Allen describes what it was like to work with so many snakes in the movie:
"When shooting the scene in the Well of Souls, your character faced off against an army of deadly snakes and spooky skeletons. Are you afraid of snakes?"
"I’m not particularly afraid of snakes. I wouldn’t want to get bitten by one or end up in a den of cobras or something, but most of the snakes that we had on the set were what are called grass snakes and they’re pretty harmless. You can put your finger right in their mouth and they won’t bite you. We had like six or eight pythons on set. They had people who watched them but sometimes there were people that got bitten by the pythons. They’re not poisonous but they have a nasty bite. The cobras had to be treated with great care because we had to have an ambulance with anti-toxins and stuff. Even if you do what’s called milking them before you work with them, they’re still very poisonous."
"So how often did you interact with snakes on set?"
"We had snakes all over us. When they would put them onto the set, they would immediately want to turn around and go away to a dark, cool spot because of the lights and it was hot there. They would bring Harrison and I into our positions, and then the guys who were looking after the snakes would come with bins with hundreds of snakes in them and they would pour them literally on me and Harrison. They would slither down our bodies, landed at our feet and then Steven would stream the action. Because if they put the snakes down first, the snakes were gone by the time they got us there. So we had to get used to it quickly. I was happy when we were with the snakes, it was challenging to work with all of those elements but I’ve never really done anything quite like that before."