Axion monodromy models can always be described in terms of an axion coupled
to 3-form gauge fields with non-canonical kinetic terms. The presence of the
saxions parametrising the kinetic metrics of the 3-form fields leads to
backreaction effects in the inflationary dynamics. We review the case in which
saxions backreact on the K\"ahler metric of the inflaton leading to a
logarithmic scaling of the proper field distance at large field. This behaviour
is universal in Type II string flux compactifications and consistent with a
refinement of the Swampland Conjecture. The critical point at which this
behaviour appears depends on the mass hierarchy between the inflaton and the
saxions. However, in tractable compactifications, such a hierarchy cannot be
realised without leaving the regime of validity of the effective theory,
disfavouring transplanckian excursions in string theory.Comment: Proceedings prepared for the "Workshop on Geometry and Physics",
November 2016, Ringberg Castl