Thornthwaite is a small village in the Harrogate district of North Yorkshire, England. It lies in the valley of Padside Beck, a side valley on the south side of Nidderdale, 9 miles west of Harrogate. Padside Beck is crossed by a packhorse bridge thought to date from the 15th century. It was probably on a packhorse route from Ilkley to Fountains Abbey, and may have …Thornthwaite is a small village in the Harrogate district of North Yorkshire, England. It lies in the valley of Padside Beck, a side valley on the south side of Nidderdale, 9 miles west of Harrogate. Padside Beck is crossed by a packhorse bridge thought to date from the 15th century. It was probably on a packhorse route from Ilkley to Fountains Abbey, and may have been constructed by the abbey. The bridge is a scheduled monument.