  Almost 35 years since their suggestion as a good solution to the strong
CP-problem, axions remain one of the few viable candidates for the Dark Matter,
although still eluding detection. Most of the methods for their detection are
based on their coupling to photons, one of the most sensitive ones being the
helioscope technique. We report on the current status of the CERN Axion Solar
Telescope and the future International Axion Observatory (IAXO). Recent results
from the second part of CAST phase II, where the magnet bores were filled with
3He gas at variable pressure achieving sensibilities on the axion mass up to
1.2 eV, are presented. Currently, CAST is expecting to improve its sensitivity
to solar axions with rest mass below 0.02 eV/c^2 after the upgrade of the X-ray
detectors and with the implementation of a second X-ray optic. At the same
time, it is exploring other possibilities at the low energy physics frontier.
On the other hand IAXO, the fourth generation axion helioscope, aims to improve
CAST's performance in terms of axion-photon coupling by 1-1.5 orders of
magnitude. The details of the project building a dedicated magnet, optics and
X-ray detectors are given.
