| Ullum | |
| Settlement Type: | Department |
| Subdivision Type: | Country |
| Subdivision Name: | Argentina |
| Established Title: | Established |
| Established Date: | 17 December 1869 |
| Seat Type: | Seat |
| Seat: | Villa Ibañez |
| Leader Title: | Mayor |
| Unit Pref: | Metric |
| Area Total Km2: | 4397 |
| Population Total: | 4498 |
| Population Density Km2: | auto |
| Population Demonym: | ullunero/a |
| Postal Code Type: | Postal Code |
| Postal Code: | 5400 |
| Postal2 Code Type: | IFAM |
| Postal2 Code: | SJU01 |
| Area Code Type: | Area Code |
| Area Code: | 0264 |
| Blank Name Sec1: | Patron saint |
| Blank Info Sec1: | Virgen del Carmen |
Ullum is a department of the Argentinean province of San Juan. It is located in the center of the province and its landscape is dominated by mountains and low vegetation. Its seat is Villa Ibáñez. It is also characterized by the production of grapes and fruit. The San Juan River is dammed by the Ullum Dam.
The name of this department is of Indian origin, translated as head of the penis. This may refer to the place where rituals were held for aspiring young Aboriginal warriors or to the fertility of the land in the area, alluding directly to male fertility.[1]
The department is located in the center west of the San Juan Province, northwest of the City of San Juan. It has a surface area of 4,391 square kilometers. It is bordered by:
Ullum is entirely located on the center and foothills of the San Juan Cordillera. Between the mountains are prominent hills: the Lomadas de Las Tapias, Talacasto, Dehesa and Villicum to the east and the Sierra del Tigre and Sierra de la Invernada to the west. In the south of the department the San Juan River is dammed by the Ullum Dam.
The climate is arid with little precipitation. Temperature ranges from 35C in summer (with highs up to 40C) to 16C during the dry winters, with lows of -8C. The climate is influenced by the Ullum dam lake and by occasional snowfall in the Talacasto area.
The flora is characterized by xerophytes. The fauna includes species such as hares,puma, viscachas, Elegant Crested Tinamous, guanacos, various forest birds and silversides.