  We present multi-instrument observations of the disc around the Herbig~Ae
star, HD~145718, employing geometric and Monte Carlo radiative transfer models
to explore the disc orientation, the vertical and radial extent of the near
infrared (NIR) scattering surface, and the properties of the dust in the disc
surface and sublimation rim. The disc appears inclined at $67-71^{\circ}$, with
position angle, PA\,$=-1.0-0.6^{\circ}$, consistent with previous estimates.
The NIR scattering surface extends out to $\sim75\,$au and we infer an aspect
ratio, $h_{\rm{scat}}(r)/r\sim0.24$ in $J$-band; $\sim0.22$ in $H$-band. Our
GPI images and VLTI+CHARA NIR interferometry suggest that the disc surface
layers are populated by grains $\gtrsim \lambda/2\pi$ in size, indicating these
grains are aerodynamically supported against settling and/or the density of
smaller grains is relatively low. We demonstrate that our geometric analysis
provides a reasonable assessment of the height of the NIR scattering surface at
the outer edge of the disc and, if the inclination can be independently
constrained, has the potential to probe the flaring exponent of the scattering
surface in similarly inclined ($i\gtrsim70^{\circ}$) discs. In re-evaluating
HD~145718's stellar properties, we found that the object's dimming events -
previously characterised as UX~Or and dipper variability - are consistent with
dust occultation by grains larger, on average, than found in the ISM. This
occulting dust likely originates close to the inferred dust sublimation radius
at $0.17\,$au.
