Fantastical pyramids like those found in South America, Egypt and Asia are simply impossible to build in Arctic and Antarctic locations with the technology available to the historical habitants of those areas. That's why you can't find anything.

1. Materials and tools. The materials pyramids are constructed from are typically obtained from quarries — open pit mines in the ground. This is... not very possible, to say the least. The grounds of extremely cold places like the Arctic and Antarctic are permafrost: soil whose groundwater is totally frozen. The peoples of the Arctic didn't have tools that would have allowed them to easily get through this permafrost, much less harvest rock for pyramids. Only some groups had access to metals like iron (see: the Cape York meteorite), and none had advanced forging available to them to refine metals for greater use.

2. Work environment. The Arctic environment maintains a very high and consistent level of deadliness that workers would have to work through, which is nigh impossible. In contrast, most if not all pyramids were built in environments that didn't actively kill people.

3. People. There has been no record of any permanent or long-lasting human habitation in Antarctica. As for the people of the Arctic, there's plenty of evidence for habitation but none on the scale of a permanently established city. The pyramids you describe took a ton of time and labour to make, from populations that simply did not exist in the Arctic.