This area is situated around Old Faithful and contains perhaps the most exciting range of thermal areas to be found anywhere in the park. These can be explored by two boardwalk loops, each of which will take over two hours to complete. The main feature is of course Old Faithful, which erupts approximately every 80 minutes. The times of the next eruption can be found in Old Faithful Lodge. This geyser can erupt up to an average of 130 feet and eruption last from ½ to 5 minutes. It has been erupting as regularly as clockwork since 1870. The next most impressive geyser is Castle Geyser that erupts with water and steam. It can shoot water as high as 80 feet into the air and lasts for as long as 30 minutes followed by more than an hour spouting steam. As it changes from the water phase to the steam phase it is at its most impressive. Shoot it against the light hiding the sun behind the steam. If you continue north along the tarmac loop road after about ½ mile you will reach the Daisy Geyser Group. A short distance from this is the splendid Grotto Geyser, which spumes water and steam from the many holes in the cone. It is a very noisy geyser, which is almost continuous.

A short walk from here is Riverside Geyser, which is situated on the east bank of the Firehole River. This erupts with a 75 feet column that falls into the river. It erupts approximately every 6½ hours and is best photographed from the bridge that crosses the river just to the north. From the bridge it is a short walk to the Morning Glory Pool. So named as its colour and shape look like the flower of the Morning Glory plant. A wide-angle lens of about 20mm is needed and care should be taken to avoid the fence and the shadow it casts.

On the return journey you follow the east loop, which passes Giant Geyser that has been dormant since 1955. Its broken cone is 10 feet high and 78½ feet in circumference. The route takes you across the river past Oblong Geyser and Beauty Pool to a concentrated area of small thermal activity which include, Spasmodic Geyser, Grand, Rift and Penta Geysers as well as Scalloped Spring and Churn Geyser before you return to Castle Geyser.

The smaller loop takes you from Old Faithful past Cinnamon Spring to a boardwalk loop on the east side of the Firehole River directly opposite Old Faithful. This area is known as Geyser Hill, here you can find some of the most exciting of thermal areas, which offer an immense opportunity for detailed photography. Amongst these are Heart Spring, Beech Spring, Pump Geyser, Teakettle Geyser and the famous Beehive Geyser. You need to allow a good 2½ -hours to complete the loop.