The most important piece of equipment you would need to go into a cave would be flashlights. A long time ago, cavers used torches for light. Miners and early cavers used carbine lights, which are still used today. The carbine lamp is a small carbide flame, like a small torch. Today, people use flashlights and lights that go on their helmet. There are two basic kinds of helmet lights. One is the carbine light and the other is the electric light. You should take two backup lights. One should be matches and a candle in waterproof jar. The other should be a flashlight with good batteries.
You would need to wear a helmet or hard-hat with a spot to put a headlight. You would want a chin strap on the helmet so it doesnt fall off in a ditch of water. You would need to wear shoes with good grips on the bottom. The shoes should be about up to your ankle. You might want your shoes to be waterproof. You would want to take old long sleeve shirts, long pants, and gloves no matter what the weather is outside the cave. You should wear two pairs of socks, elbow pads, and knee pads. You should take a backpack to carry things and a camera to take pictures.
You should also take food and a water bottle. Experienced cavers would take a light weight ladder. Some people use a handline which you use in slippery places. Also experienced cavers might take a small cooking stove.
Some cavers need an inflatable boat. You would also need a rope, a map of the cave, and a small first aid kit. You might want to take replacement pieces for a carbine lamp if one is being used.
The main features of a cave are the entrance, chambers, stalagmites and stalactites, and underground water.
There are three types of entrances. The first one is a sinkhole. You might need a rope to lower yourself into a sinkhole. The second is an opening in a cliff which you could walk into. The third is an underwater opening which you might need to swim into from a lake or river.
The chambers are the rooms and passageways within the cave and they come in many different sizes. The passageways can be so small that only an animal could fit through or so big that a group of people could walk through. The chambers can be very big or very small. Some caves like Mammoth Cave have chambers so big they could hold many football fields.
The most common feature of a cave is the stalagmites, stalactites and columns. Stalactites are like icicles and hang from the ceiling of the chambers. Stalagmites grow up from the ground. Columns are made when stalagmites and stalactites are connected. A stalactite forms just like an icicle only it is made out of limestone.
Underground water flowing into caves can be waterfalls, pools, streams, rivers, and lakes. The waterfalls are formed by water flowing into the cave from a hole or going off an edge in a cave. The streams and rivers are formed by water flowing through a passageway. When it reaches a chamber it forms a pool or lake.
Many types of animals live in caves. Like mammals, amphibians, reptiles, birds, and fish. Invertebrates like spiders, snails, and bacteria also live in caves.
Bats, which are mammals, are very popular in caves. Some bats that live in caves are long-eared bats, big brown bats, gray bats, pipistrelle bats, and little brown bats. Bats are blind and find there way around by making noises through their throats and listening to the echo. Bats eat insects in the cave and out of the cave. Bats hang up side down to sleep.
Bears, which are also mammals, hibernate in caves during the winter. Hibernation means they dont leave the cave during the winter. The bears eat all through the summer so they are not hungry in the cave. The rocks in the cave store heat from the summer and in the winter the rocks slowly release the heat to keep the bear warm.
Many invertebrates live in caves. Some feed out of the cave and some feed in the cave. Grasshoppers and crickets feed out of the cave but dung-beetles eat in the cave. Flesh eating beetles eat the flesh of dead bats.
Caves that have water will usually have fish in them. The fish found it was easier to live in the cave because there are no badgers, bears, and other big fish to prey on them. They stay in the dark parts of the streams. Some fish in caves are blind.
Two types of birds that live in caves are barn owls and swiftlets. The swiftlets build their nests out of saliva. The barn owl leaves the cave to find food. Then it flys back to the dark part of the cave.