The best known ancient Greek pyramid is known as the Pyramid of Hellinikon . In the time of the geographer Pausanias it was considered to be a tomb.
The age of this structure is a matter of some controversy as various dating methodologies have provided conflicting results. But the most likely estimate is that it was built some time in the 4th century BC. However some archaeologists have argued that it dates as far back as the third millennium BC which would mean its construction corresponded with those in Egypt. This would provide some support for the mythological links supposed to have existed between Egypt and Argos.
As with other Greek pyramids the size of the one at Elliniko is considerably smaller than those in Egypt; the external base is just 7 metres by 9 metres. Another difference is that it did not have a pointed top. The walls slope at an angle of 60 degrees for 3.5 metres after which there was a flat surface. Internally there is a narrow corridor leading off the entrance at the South East side of the pyramid. This corridor provides access to the main interior room which is around 7 metres square.
References:House of the Blackheads (Melngalvju nams) is a building situated in the old town of Riga. The original building was erected during the first third of the 14th century for the Brotherhood of Blackheads, a guild for unmarried German merchants in Riga. Major works were done in the years 1580 and 1886, adding most of the ornaments.
The structure was bombed to a ruin by the Germans June 28, 1941 and the remains demolished by the Soviets in 1948. The current reconstruction was erected from 1995 to 1999. Today the House of Blackheads serves as a museum and sometimes concert hall.