What were the geographical obstacles faced by panama canal builders?

Obstacles might include mudslides, passing through a mountain range, different levels of land and lakes, diseases that affected workers, and the opposition of the Colombian government to the presence of the United States in the region. Engineers had to build a dam, design and build locks, and remove huge amounts of earth and rock. A medical obstacle is that scientists had to develop vaccines and medications to treat the disease malaria that affected many workers. A political obstacle was that the government of Colombia did not allow the United States to build the canal. The United States helped Panama revolt against Columbia, and Panama gave the United States the permission it needed.