Monks Mound

Mountain Largest Mississippian earthwork at the Cahokia site

Largest pre-Columbian earthwork at Cahokia near Collinsville, Illinois; visitors climb viewing platforms, visit the interpretive center and study Mississippian archaeology.

Monks Mound is the largest prehistoric earthen construction in North America north of Mesoamerica, located within the Cahokia Mounds State Historic Site in Illinois, United States. The structure is an immense stepped earthwork built by the Mississippian culture and dominates the Cahokia plaza complex.

The mound rises to about 30 metres (100 feet) and its base covers roughly 14 acres (about 5.7 hectares), making it the largest monument of its kind in the region. Visitors follow interpretive trails and use the visitor centre to understand the mound’s scale and the wider complex of platform mounds, plazas and residential areas.

Archaeological evidence shows Monks Mound was constructed in multiple stages during Cahokia’s peak occupation, roughly between AD 900 and AD 1200, serving as a central ceremonial and political platform. The site has been the focus of archaeological study and public interpretation since the 20th century.

Monks Mound sits within the Cahokia Mounds State Historic Site near Collinsville, Illinois, on the east bank of the Mississippi River opposite the St. Louis metropolitan area, a short drive from downtown St. Louis.

  • Construction period: Constructed in multiple building stages by the Mississippian culture, the mound dates to the site's peak between about AD 900 and AD 1200.
  • Viewing points: The best panoramic views of the mound and surrounding plaza are available from the visitor centre and the mound's public viewing terraces; check the site's opening hours before visiting.

What to See #

  • Monks Mound: An earthen platform mound built by the Mississippian culture, rising approximately 30 metres (100 feet) above the surrounding plain with a base footprint covering roughly 14 acres (about 5.7 hectares).
  • Visitor centre and trails: The nearby visitor centre and interpretive trails at Cahokia Mounds State Historic Site provide exhibits, a short film and viewpoints of the mound and surrounding earthworks.
Monks Mound
Cahokia Mounds State Historic Site, 30 Ramey St, Collinsville, IL 62234, United States
38.6603, -90.0618
Cahokia Mounds State Historic Site (interpretive center) Tue-Sun 9:00am-5:00pm, closed Mondays; grounds open daily sunrise-sunset (hours vary seasonally)
Cahokia Mounds State Historic Site: general admission around $9-$10 for adults; discounts for seniors and children; some events have separate fees

How to Get to Monks Mound #

Cahokia Mounds is in Collinsville, Illinois, about 15-20 minutes east of downtown St. Louis by car. From I‑255 take exit 1B to Ramey Street; the site is clearly signed. Metro area public transit connections exist but are limited-driving is the most common option.

Tips for Visiting Monks Mound #

  • Climb Monks Mound early in the morning for the best views; the summit stands roughly 30 meters (100 feet) high and offers a rare vantage over the city's plan
  • Visit the Interpretive Center to see reconstructions and artifacts that explain Mississippian life, including replica wooden structures and pottery
  • Allow at least two hours to walk the trails and read the site plan-the scale of Cahokia is easy to underestimate

Best Time to Visit Monks Mound #

Best in spring and autumn for comfortable weather and dramatic landscape views.

Spring
April-June · 10-25°C (50-77°F)
Mild weather and spring greenery make the earthen mounds dramatic against the sky.
Autumn
September-October · 10-22°C (50-72°F)
Clear air and fall colors add texture to the mounds and trails; popular for photography.
Summer (early morning visits)
June-August · 22-32°C (72-90°F)
Hot afternoons; early mornings are best for climbing and exploring before heat builds.

Weather & Climate near Monks Mound #

Climate

Monks Mound's climate is classified as Hot-Summer Continental - Hot-Summer Continental climate with hot summers (peaking in July) and freezing winters (coldest in January). Temperatures range from -7°C to 32°C. Moderate rainfall (969 mm/year).

Temperature & Rainfall
Temperature Range
32°
Warmest Month
-7°
Coldest Month
Monthly Conditions

January

January is the coldest month with highs of 3°C and lows of -7°C. Moderate rainfall (51 mm).

Comfort

-2°
Feels Like Freezing
-2°C
Temperature
-7°

Weather

51 mm
Rainfall
4.0 m/s
Wind
Light Breeze

February

February is cold with highs of 6°C and lows of -4°C. Moderate rainfall (56 mm).

Comfort

Feels Like Cold
C
Temperature
-4°

Weather

56 mm
Rainfall
3.9 m/s
Wind
Light Breeze

March

March is cold with highs of 13°C and lows of 1°C. Regular rainfall (88 mm).

Comfort

Feels Like Cold
C
Temperature
13°

Weather

88 mm
Rainfall
4.2 m/s
Wind
Light Breeze

April

April is cool with highs of 19°C and lows of 7°C. Regular rainfall (94 mm).

Comfort

13°
Feels Like Cool
13°C
Temperature
19°

Weather

94 mm
Rainfall
4.2 m/s
Wind
Light Breeze

May

May is mild with highs of 24°C and lows of 12°C. The wettest month with heavy rain (102 mm).

Comfort

18°
Feels Like Mild
18°C
Temperature
12° 25°

Weather

102 mm
Rainfall
3.3 m/s
Wind
Light Breeze

June

June is mild with highs of 29°C and lows of 18°C. Regular rainfall (94 mm).

Comfort

23°
Feels Like Mild
23°C
Temperature
18° 29°

Weather

94 mm
Rainfall
2.9 m/s
Wind
Calm

July

July is the warmest month with highs of 32°C and lows of 20°C. Regular rainfall (94 mm).

Comfort

26°
Feels Like Warm
26°C
Temperature
20° 32°

Weather

94 mm
Rainfall
2.5 m/s
Wind
Calm

August

August is warm with highs of 30°C and lows of 19°C. Regular rainfall (82 mm).

Comfort

25°
Feels Like Warm
25°C
Temperature
19° 31°

Weather

82 mm
Rainfall
2.4 m/s
Wind
Calm

September

September is mild with highs of 27°C and lows of 14°C. Regular rainfall (82 mm).

Comfort

21°
Feels Like Mild
21°C
Temperature
14° 27°

Weather

82 mm
Rainfall
2.5 m/s
Wind
Calm

October

October is cool with highs of 21°C and lows of 8°C. Moderate rainfall (69 mm).

Comfort

14°
Feels Like Cool
14°C
Temperature
21°

Weather

69 mm
Rainfall
3.1 m/s
Wind
Light Breeze

November

November is cold with highs of 13°C and lows of 2°C. Regular rainfall (82 mm).

Comfort

Feels Like Cold
C
Temperature
13°

Weather

82 mm
Rainfall
3.7 m/s
Wind
Light Breeze

December

December is cold with highs of 6°C and lows of -4°C. Moderate rainfall (75 mm).

Comfort

Feels Like Cold
C
Temperature
-4°

Weather

75 mm
Rainfall
3.8 m/s
Wind
Light Breeze

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