  In this work, we present a new mosaic created with the second release of
LOFAR Two-Metre Sky Survey data (LoTSS-DR2), which probes polarised synchrotron
emission in the high-latitude inner Galaxy. Our objective is to characterise
the observed emission through multi-tracer analysis to better understand the
volume and the structures that may be observed with LOFAR. Furthermore, we
exploit Faraday depth as a unique tool to probe the diffuse magnetised
structure in the local ISM. We produced a mosaic Faraday cube of LoTSS-DR2 data
by applying a rotation measure synthesis algorithm. From the cube, we
constructed Faraday moment maps to characterise the nature of spectra.
Additionally, we quantified the linear depolarisation canals using the Rolling
Hough transform and used them to search for alignment with other data sets.
Utilising LoTSS-DR2 observations alongside complementary data sets including
Planck polarisation data, HI emission maps, and starlight polarisation
measurements, we estimated the distance to the Faraday structures. The Faraday
cube reveals an ordered structure across two-thirds of the observed area, whose
orientation aligns well with that of both the HI filaments and the magnetic
field. We estimate the minimum distance to the Faraday structures to be between
40 and 80 pc, which puts them in the vicinity of the Local Bubble wall. The
emission is organised in a large gradient in Faraday depth whose origin we
associate with the curved wall of the Local Bubble. Comparing our data with a
model of the Local Bubble wall, we conclude that we might be probing a
contribution of the medium inside the Local Bubble cavity as well,
corresponding to the complex of local interstellar clouds. Moreover, we propose
a toy model incorporating an ionised front of finite thickness into the Local
Bubble wall, as a curved, cold neutral shell alone is insufficient to produce
the observed gradient.
