What are the advantages and disadvantages of overhead vs underground power lines?

Overhead lines are less expensive to install (5-10x cheaper), easier to repair, and naturally cooled. Disadvantages include visual impact, vulnerability to weather, and right-of-way requirements. Underground cables are protected from weather, aesthetically preferred, and safer from contact. However, they cost more, are harder to locate and repair faults, require insulation for heat dissipation, and have shorter lifespans. Underground is common in urban areas.