Casma is a quiet town on Peru's north coast between Lima and Trujillo. It would likely get bypassed by tourists if not for the stupendous archeological site of Sechín just a few miles outside.
The only practical option to travel the 229 miles (368 km) from Lima to Casma is by road. This is because the total overland journey time is 5.5 hours, while Casma's nearest airport is in Trujillo, which coming from Lima is three hours drive north beyond Casma. Road transport options include either private transfer the whole way or bus the whole way.
Casma is a worthwhile stop on any tour around Northern Peru: see this 14-day itinerary for more about the region.
By Private Transfer
Duration: 5 hours
Having a private car and driver is more convenient and comfortable than taking the bus; that said, there is not much to see between Lima and Casma, so having a vehicle that will stop for you en route is not so much of an advantage. Barranca and the nearby archaeological sites of Paramonga and Caral are some of the places to stop en route. Hwy Pan-Americana Norte runs the whole way along the coast from Lima to Casma, and this road is one of Peru's better roads.
This would be by far the most expensive means of transport, but it would, if you went direct, also be a bit quicker.
Duration: 5.5 hours
There are direct buses from Lima to Casma, but these are relatively few, and rather than waiting around for one of the few direct connections it is often better to hop on one of the regular buses bound for Chimbote, a major port city one hour north, and ask the driver to let you out on Hwy Pan-Americana Norte at the Casma turn-off.
Casma's main bus terminal is at the southern end of town, close to Hwy Pan-Americana Norte. This is the cheapest option for travel between Casma and Lima.