The last 10K of the year is the Carrera San Silvestre, run on December 31st. It starts in the Guatemala Municipal Building, finishes at Mateo Flores Stadium. Inscription ends on december 28th. You can pay at any Bantrab Q60.00 You will need an IPU number that you can ask as +502 2200-5252, to make the payment.
It is a fun race where you can run with a costume, it starts at 14:30 for women and 14:40 for men.
There is also version of this run in Cobán, you can find more information here: